Originally posted by ngdh
Fair point Tamil,

I guess I was more interested in any theories that would prove or disprove my colleagues assertion that a "clashing transaction" caused the error.

AFAIK the hash area requirement would be allocated from process memory so it couldn't be affected by multiple processes running concurrently.

Any thoughts?
I believe the concern of this thread was already addressed by Tamil, it should be your colleague's turn to give supporting docs to support his theory about "clashing transaction"