So she didn't respond, he got caught and suddenly sees the light...
I am sorry, but I would be very cautious here.
Sounds more like he is playing nice so he doesn't have to pack his bags.
IMO you NEVER give an ultimatum/threat you are not going to enforce.
I would be watching closely...
I understand the pain,it sucks but you are better than someone's back-up plan.
(((hugs))) I hope he is being honest.