I was approaching 7B2 today to land on 14, and on final ahead of a student at this point on downwind doing touch and goes. I announced my positions, as was the student. They seemed to be heeding my calls but not responding, even though I heard them on CTAF and the FBO confirmed that they heard me. When I landed I was on the active and heard the student call that they were on short final. I was past the turn off and headed for the key at the end of the 3k ft strip, to taxi back. Not having heard anything from the plane on short final, that announced the intention for a touch and go I held in the key area where 10 seconds later they landed and departed. I typically fly out of a towered field, so this behavior of having a touch and go use a runway with another aircraft on it even if taxiing seems odd and contrary to safety. I really would have expected them to go-around even though I signaled my intention to turn around in the key area but didn't do anything to signal that they were clear to land. Is this common for untowered fields where backtaxi ops are required?