Hey Flanker,
I know you are done with this but I'll make a few points. The relative levels of experience or cpl vs ppl has nothing to do with right and wrong, what rules apply or the amount of leeway you get. If his flight had any form of priority he should communicate that to you. You fulfilled your requirements (more than minimum really) and had better situational awareness, I think a well done for potentially avoiding an accident is in order and if more ppls were as aware it would make many cpls happier!!
One more thing, this happens everywhere in all operations. Just recently a jet taxied out at a busy WA ctaf, we could see them as we were coming in, they did a ctaf taxi call, No call on center until they had backtracked and lined up (dodging cobt I imagine) then no other calls on ctaf. The only way we would separate was visually. This is not some small time jet operator either.
You just have to manage on the day, like you have, and if it's a close call talk to them or report it.
Cheers