The Facts huh?  OK, first off in Illinois it is going to involve at least a county cop and most likely a state trooper because the officer was involved ... even though he was not in either vehicle.  So when the state trooper gets there most likely the driver of car 1 gets a ticket for an expired 30 day tag unless it can be verified a plate is ordered and just not here yet. If it has been received he gets a ticket for improper display.  Person driving car 1 gets a ticket for a revoked drivers license.   Driver of Pickup 1 probably gets a ticket for failure to yield ... depends on the mood of the trooper and the intersection.

Who's liable and for what?..........why?..............again I'm thinking Illinois.  I believe we are a no fault state.  If you want your car fixed you buy insurance on it.  If the other guy is uninsured, you need to carry uninsured motorist coverage.

Merely hypothetical ? Sure, Rich.  Whatever you say ...