I haven't looked at any tables for a while but I think 45 minutes at 134 (?) F is insufficient for a generally-accepted safe reduction of salmonella and e. coli.
Your talking about hamburger where all parts of the meat have had a chance to be exposed to air, with a steak it's safe to eat it rare/ medium rare because your cooking the external part which will kill any bacteria on it's surface and the meat in the middle will be safe because it has not been exposed to air other parts of meat to spread any pathogens..
