since i do not know what 'that' is I guess you mean 'sen a biot causing an interrupt.

I can give you an actual case:

a system with a very complex serial data format that had to be processed as fast as possible BUT processing it all in the UART ISR starved other events too much.

solution:
set all interrupts except (the unused) T1 at high priority and make the UART interrupt do just the basiccs and then set TF1. Do the remainder of the record processing in the T1 ISR.

Erik