While obviously there's a variation between different services, where there are going to be passengers left on the platform does anyone know if it would generally be cheaper for a TOC to declassify first and refund the first class ticket holders, or to pay delay repay to the people left on the platform?
Or pay for the delay caused to other services because the overcrowded train was not able to leave on time - very likely if the train staff don't declassify first class and there are queues of people asking "can you move down" and being told "no" whilst there is plenty of room in first.