Another question in regards to OP's situation is where were the crutches put? I suppose they could have been placed in overhead bins....surely the passenger wasn't allowed to keep them and thus breaking another rule of emergency exit seats in keeping the floor clear. It does occur to me that the passenger concerned may well have been able bodied when they bought their ticket and selected a seat, but broke an ankle or similar subsequent to that. The crew really should have done something on safety grounds.