General aviation pilot reported a possible traffic conflict with helicopter during approach to RNT airport.

Narrative

While on an instrument flight plan from S43 to ZZZ with a coworker we decided to return to S43 through RNT. We were on the RNAV GPS 34 into RNT and got cleared in then sent to the CTAF at around 1600ft MSL. Upon switching frequencies and calling our final we heard a helicopter in the downwind call to tell us they would follow us in. There was also a Pilatus PC-12 at the hold short waiting for the landing traffic. They alerted us they had a 4 minute clearance time so I wanted to make sure to get off the runway as soon as possible for them. Upon landing I exited to the west side of the runway on A5 and began taxiing back toward runway 34 so that we could file our new IFR flight plan. The clouds that were to the north prevented us from flying VFR back to our destination of S43. As soon as we taxied back toward the runway we heard a call from the helicopter saying 'thanks for cutting me off on final' and we saw them about 100ft above us over taxiway A. I apologized over the radio then we proceed to file our flight plan; get our clearance and depart. Someone called the facility we rented the aircraft from to complain and that is how I heard there may be an issue. I looked at the right of way rules and could not determine if either aircraft was directly at fault. This report is being submitted because I am unsure of who is at fault but wanted to alert the authorities of the incident.