Most likely. The DH proc killer does jump in and make its presence known from time to time
Unfortunately, AFAIK, Dreamhost has never published these particulars; users have reported various experiences with the "murderer" and I suspect that it has been tweaked over time.
Years ago, people rarely saw it but of late it has been more visible. I suspect that is the natural result of increased loading on the servers due to Dreamhost's growth.
Some have reported success by severely "niceing" their processes, though YMMV. You also might find more current info on this on the Dreamhost IRC channel, where this subject pops up from time to time. Good luck, and if you are able to locate any "hard limits", please share the info!