right now the exception message shown is "Bad log priority".

But that may not be the actual reason for the error. Suppose in my code I have

$log->addEventItem('foo','bar');

This would throw the "Bad log priority" exception message since __call() is overridden to provide a convenience method for doing $log->priorityName('message'); instead of $log->log('message', Zend_Log::PRIORITY_NAME);

the current exception message thrown isn't helpful because it is context sensitive. A more useful message would be "__call() is unable to trap the method $method" or something to that effect.