It seems to me that the foreman misrepresented his memory of what happened with his own patent as fact to the other jurors to be applied to the current case; and he got some stuff wrong. It should be made possible in highly complicated cases like this that the jury could bring in experts (with the judge present maybe) to explain the real facts. Or for the jury to ask questions to the witnesses/judge during the trial to obtain clarifications they need to make their decision.
Juries are allowed and often requested to ask questions of the judge during deliberations, but it's up to them to decide that they need that clarification.
I've never been on a jury in a trial such as this, but just as you'll find in regular conversations, members of a jury will present themselves as experts and spout "facts" to back themselves up. A confident "expert" can convince a lot of people.
