Once you hit 165 bacteria is dead. Also if you spend a long time in the 145 range bacteria will die. That's why you can cook chicken in a 145 water bath via sous vide.I am very anal about that sort of thing (you don't want to see me cooking chicken) so watched very carefully the first time. I found/find that it still speeds through that zone at a good enough clip to be safe. The addition of a long time at 140+ keeps it safe.
This is the sort of reason I'll never be a "jiggle" or "by feel" guy, I always use my Signals with it's pretty graphs and alarms.