[seL4] Capability faults on seL4_Send and seL4_Call

Hi all, I understand that capability faults for seL4_Send and seL4_Call only happen when the look-up fails, and not when illegal operations are attempted, such as calling a null cap or a piece of untyped memory. Is there another way at all, then, that such errors can be handled by user-level code? This is part of a project where the faulting process needs to surrender control to another process whenever it performs a system call on an invalid capability. Is there a way to achieve this given that fault endpoints will not work? Thanks, David