You might want to double-check the time of a known call (like yours when he clicked over and asked if he could call you back) against those call records. Sometimes the phone provider's server is off (it has been on mine before).
Assuming the times are all legit, then he's lying to you. What are the possible reasons for that? Could be OW, for sure, but also could be something else he chose to keep private from you.
I'm confused, tho -- if you can check to see when he called his mom, why can't you see who it is he was talking to when you called him? I'm missing something.
