At the moment when PT_USERMEM or PT_USERTIME are exceeded you just get a message telling you which process has exceeded the limit.
Could more debugging info be included such as a trace of the process causing the memory limit to be broken?
For example, I've had a couple of users go past a 200MB limit with a particular Joomla/Virtumart install. Normally it runs in less than 15MB but very occasionally it's going past 200MB for no obvious reason. Debugging it is almost impossible to catch since it seems to be a very quick script that allocates a lot of ram.
Or perhaps this should be a trigger for another script such as PT_LOAD_ACTION ?