Has this happened before, and can you duplicate it?
The only thing I can think of is the user at 207 has DEE or is call forwarding outside the system, and when you called in it grabbed another trunk to dial out but there was a call being presented to the system, the telco just hadn't sent the ring voltage yet, and BINGO, your incoming call is connected to another incoming call. Classic loop start call collision... a rare occurrence but can definitely happen. Nothing you can really do about it, without advanced call state supervision like PRI or SIP trunks, it can happen.
If this happens a lot, then it's a sign of insufficient number of trunks for the setup, you can add more trunks or remove the users ability to use things like DEE or Call Forward off-premise.