Discussion Discussion of reasonable experience during MP with lag?

I am looking for some feedback on what should be expected in a MP scenario with significant lag. I am prototyping the netcode of my game at the higher level (client prediction, etc.), not the transport level.

If I have two players across the net shooting each other and one ducks behind a wall, he could still be hit after he is behind cover due to lag, and that is acceptable if it happens immediately. The experience between the two players is resolved and to the server and other players the resolution seems reasonable, clean, and generally not noticed by anyone but the one who got hit.

But what if they are both in vehicles moving a bit faster than walking across the terrain? In this scenario, A t-bones B near B's rear bumper. From A's perspective, A is running slightly ahead of the server and more slightly ahead of B. From B's perspective, B is running slightly ahead of the server and more slightly ahead of A. While A's experience is hitting the tail fender of B, B's experience could be that A was never close enough and that B had already moved ahead enough to clear A's path. From A's perspective, B's vehicle is spinning from the collision and is now moving in a different vector due to the forces applied by the collision. But B doesn't see this, and it isn't clear to either A nor B what the server or others might see.

Given the experiences of A and B being significantly different with those differences being significant to the environment (two large vehicles moving across the world), and that of the server and other players being potentially even more different, what should I expect as a reasonable resolution? I am not asking how to resolve this, but what the outcome should be, or what the overall experiences of the various parties should be?