[Israel.pm] Weird '-M' file operator behaviour

[Shmuel Fomberg]

Hi.

I had a code like this in the codebase:
if (not -e $file1 or -M $file1 < -M $file2) ....

up until today, it worked. suddenly, it did not.
After replacing the -M with stat($file)->mtime(), the bug was solved.
Is there any obvious catch that I miss?

Thanks,
Shmuel.