transmission & canker sores vs. cold sores

i have herpes II. guy (lets call him joe) was fine about it one day but after a week when his girlfriend showed him a sore/blister on the inside of her mouth he freaked out that he might have infected her.  a week after she showed him her sore he developed a similar sore inside his mouth. joe got tested and he has herpes I.

i just read that cold sores develop on the outer surface of lips and rarely moves inside, that the blister inside the mouth is more likely a canker sore. how can we tell the difference?

the time line seems to indicate that his girlfriend was infected first and transmitted to joe. what are the chances that i contracted herpes I if joe and i had no contact for over 12 days before his sore.

if his girlfriend did contract herpes I first, what are the possible ways that she could contracted it besides oral sex or kissing someone with herpes? how likely is it?