Most Helpful Girl
The simple fact that he told you about her before hand, and that he put the call on speaker so you could hear the conversation, makes me believe that he is being honest with you. If you're at fault, you aren't going to put the person who could get you busted, on speaker phone so the other party can hear.
However, he didn't just 'meet her' when he had a gig, he screwed her. She wouldn't be harrassing him years later if they'd only met.