Well, if the problem is a broken pipe, why not install a signal handler to trap that error (in fact, why not install signal handlers for all the errors you might run into?). That way, if the program traps an error, it can execute any "cleanup code" that needs to be done before wiping the pid file and shutting down. I believe the syntax for a signal handler involves manipulating the "pseudo" hash %SIG and looks something like this.

$SIG{PIPE} = sub { #handle error }
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There's also a sigtrap module, you might want to check that out