If the process for patent hearings in 1976/77 was anything like the modern approach then it was probably an inter partes hearing. These require statements from those involved and supporting evidence to be gathered in advance of the hearing and shared with the other parties. Evidence consists of witness statements and supporting documents or material.
Firstly Hamish Robertson would have submitted his version to the Comptroller detailing the matters at issue, the facts upon which he was relying and the remedy sought.
The statement from Hamish would then have been passed to Jack Tiefenbrun. He would have had several weeks to reply with his counter statement. This would have stated which allegations he denied and why. He probably could have done this by including his different version of the events or by directly addressing the Hamish submission. He would have been expected to state which of the Hamish allegations he admitted to and which allegations he couldn't deny but needed Hamish to prove. If he did not contest something in the Hamish statement then the default was that the allegation was agreed.
The counter statement from Jack would then have been passed to Hamish for him to decide whether to continue. Hamish would then respond to the counter statement indicating what he agreed with and what he would contest in the same way as Jack had to respond to the initial submission.
Some further iteration between the sides may have taken place but statements would normally only be amended with the permission of the Comptroller. The intent is for both sides to go into the hearing on an equal footing with regard to the statements and evidence and to allow the hearing to focus on what was being contested. New evidence is not supposed to be submitted in the hearing itself though there is an indication that Hamish may have done this when he brought up the Harrogate 1973 confrontation with Ivor.
I uploaded copies of the Hi-Fi News coverage by Adrian Hope (aka Barry Fox) in my previous post which includes the following summary of the background provided by the Patent Officer.
"The Officer saw the nub of the disputed invention as the point contact bearing formed by the conical end of the platter spindle. And it was agreed all round that this, by minimising rumble was indeed the nub of the invention. The Hearing Officer then went on to summarize the train of events that led up to the current marketing of Linn turntables. To the best of my knowledge this has not previously been crystallised, so thanks are due to the officer for his delightfully clear summary of the situation.
Indeed, anyone both puzzled by and interested in the history of the Ariston-Linn saga need look no futher than the Hearing Officer's main decision for a full breakdown of the extraordinary facts surrounding this unique episode in Audio History.
To summarize the summary: Jack Tiefenbrun formed Castle Precision Engineering (Glasgow) Ltd. 15 years ago. Hamish Robertson had a company called Thermac in 1967 which became Ariston in 1970 and Ariston Audio in 1973. In 1970 Jack Tiefenbrun's son Ivor Tiefenbrun bought some Hi-Fi equipment and became friendly with Hamish Robertson. Ivor Tiefenbrun made a prototype turntable with a ball bearing and then went off to Israel in 1971. While Ivor was away, Jack Tiefenbrun and Hamish Robertson changed the ball bearing to a point bearing. Robertsons's company Thermac then ordered some 40 such units from Castle. Now as Ariston, Robertson then planned a display of the units for Harrogate in September 1971. C. W. and J Walker were appointed selling agents for the turntable- by now christened the RD11. The turntable was indeed shown at Harrogate that year and the RD11 sales literature boasted "a unique single point bearing" and "almost rumble free sound". The next year (1972) Jack Tiefenbrun filed the two provisional patent specifications on which the disputed patent (BP 1 394 611) was finally to issue. By the end of that year (1972) there had been a deteriation, and finally a breakdown, of relationships between Robertson and Ariston on one hand and the Tiefenbrun's on the other. This culminated with a threat to Robertson that a copyright action would be brought against him if he had the RD11 turntable made elsewhere than at Castle by Tiefenbrun. In February 1973 Linn Products Ltd. was formed to sell single-point bearing turntables made by Castle. Ariston was then taken over by Dunlop Westayr Ltd. and the separate firm Fergus Fons formed with Robertson as director. As we have already seen, it was Fons and Robertson and not Ariston-Dunlop-Westayr, who attacked the Tiefenbrun patent claims.".
It can be deduced from this summary that Jack must have submitted a statement which claimed the initial development of the turntable was a prototype by Ivor. It is also clear that in the view of the Patent Officer the Tiefenbrun version prevailed so it probably had some corroboration.
Ivor has since named former Castle staff who helped him with the development. "The design benefited from the input of my late father who designed the patented single point bearing and from the key engineering staff at Castle Precision Engineering, my late father’s company, including John Cross, Bob Hamond, George Borthwick and the late Russell Christie and Edgar Clumpas who all enthusiastically helped me with this ‘lunchtime’ project, along with many other employees at Castle".
Also elsewhere Ray Collins, a former Castle employee not named by Ivor above told Nigel Pearson that he helped Ivor with the development.
http://www.diyaudio.com/forums/the-lounge/200865-sound-quality-vs-measurements-1553.html
It is not clear from the Hi-Fi News coverage if Hamish actually submitted his own alternative version of how the turntable was developed but by introducing the Harrogate 73 confrontation it appears he was contesting that the development was done by Ivor. All the versions on the web that attribute the design to Hamish start with him approaching the Tiefenbrun's with "his" design but do not address the prior development and where it was done. The only thing I have seen pertinent to the development is that Hamish told at least one person that the turntable was based on an AR XA. It was acknowledged by the Tiefenbrun's that Hamish was responsible for the styling and the XA does have platters that look cosmetically similar although the inner platter has a totally different diameter. The spring arrangement is rotated and different, has no armboard or cross brace and a totally different t-bar sub chassis. The development of the turntable based directly on an XA if true would have required access to workshop machine tools and would have required effort and time. Apparently Hamish was unable to provide much if any of his own evidence that he developed the turntable and bearing with one of his most prominent and vocal supporters saying that this was the fault of Castle for "losing" that paperwork. For the types of business transactions described by Hamish supporters we should expect product specifications, quotes, orders, correspondence and receipts with copies held by both sides so the apparent inability of Hamish to produce his own copies of such paperwork must be a concern.