Speed bump is an old phase used by many in the emergency services.  Part of what keeps emergency workers sane while dealing with the horrible things they are exposed to is to use dopey phrases amongst themselves.   It may not be politically correct but I can tell you from experience, morbid humor sometimes helps when you've just seen something horrific.  I guess in today's snowflake environment nothing gets a pass.  Thank God he didn't call the firefighters dodo faces, that would be grounds for termination.