So one is allowed to execute code AFTER exit has been called even if it is an ASCII string inside a variable, from awk AND Python and I thought Python was strict, what about Perl and others?
You don't "execute code AFTER exit" - you add one (or more) routines to the sequence of tasks the programme has to perform before giving control back to the caller, e.g. closing files, releasing locks, freeing allocated memory. If it is a write, you'd mayhap do it before stdout is closed, if it is just a number, you reference it just on exiting.
Awk's exit is a statement and Python's is a function.
Both - whatever they are - start quitting the programme.
Maybe it is just me but this should never be allowed to happen if the RC is not an integer.
Pascal wouldn't allow non-integers, C mayhap would - python might be somewhere in between.