thanks for doing
 

-Thanks, Peter, for drawing my attention to the problem.

The teacher is announcing something to the student, obviously not addressing Peter, so do you think the two commas are wrong and should be deleted?

Re: thanks for doing
 

As this is spoken English, commas are irrelevant. In a transcription they can only indicate pauses in speech. Thus think the most likely reflection of what the teacher said would be :
Thanks Peter, for.....
but the two pauses are certainly possible.

But why do you say the teacher is not addressing Peter?? it seems to me s/he is. If s/he was "announcing" something, it would be to the whole class, and s/he would say :
Thanks to Peter for...

Re: thanks for doing
 

Good answer. Thank you.