Truck wins
Truck tries to merge, car behind me decides to close the gap, truck merges anway and forces car into blocked lane.
Couple of things in this clip for argument's sake:
Truck merges across 2 lanes but doesn't disable and re-enable indicator like you're supposed to. So to other drivers it becomes unclear if truck wants to merge again or has simply left indicator on by mistake.
Car behind me doesn't have to leave a gap, but it appears like they speed up to actively stop the truck from merging. Possible they didn't realise truck wanted to merge though because of point 1.
Ultimately the truck "pushes in" dangerously and the car is forced to yield.
My take: Car should have cautiously assumed the truck was making a merge in order to take the next right turn, and left a gap. No obligation to but just in the spirit of "sharing the road".
Truck definitely at legal fault and driving dangerously - should have yielded after car honked but didn't give a shit about safety.