One question, if only 'external lawyers' are allowed to the the prototypes of 'the other' company - how the hell do those lawyers decide what was copied or not - I would assume those have not the technical background and company internal information to make an educated decision, I mean, a more technical person with internal knowledge from each company would be required for that - but that person would no longer be allowed to work on the new version ....
Most of these IP Lawyers have backgrounds in the technology. Some have PhDs and JDs. Outside Counsel is almost a pre-requisite for this type of litigation. Internal Counsel supervise the work, but the outside counsel does all of the analysis with experts. There is no disclosure on infringement, just that they are pursuing it.