Oh I see, I thought getting an error that caused the python code execution to terminate was considered a "crash".

On the note of whether you should fix this I think the answer is yes. When I call pool.apply_async() I expect it only to return when the worker process has been started and finished it's initialization process (i.e. sending the incr-ref request). That being said I could see people wanting to utilize the minor performance gain of having the worker start AND run asynchronously so I think this option should be available via a boolean arg to apply_async() but it should be off by default because that is the safer and intuitive behavior of apply_async().