Comment by compiler-guy

Part of the Statute of Limitations isn't just on when he filed the claim, but when he found out or should have found out, by reasonable diligence that he had a claim at all.

So the question before the jury has a significant component of "Should he have found out by this time?" Which is a question of fact, and facts are typically decided by juries, in the US at least.

The two parties can agree together to let a judge decide facts like this, but generally, if one or the other party wants it to go to a jury, it does.

I'm guessing part of Musk's strategy was to have it go to the jury, which are often seen as easier to manipulate than judges, especially when a case is weak. Or perhaps his team already knew this particular judge would be inclined to rule against him, so did the next best thing.