A twin engine turboprop pilot reported they were holding in position to give way to another taxiing aircraft when that aircraft passed so close to them they '...felt a buffet and left yawing sensation that led them to suspect the wing tips had touched.'

Narrative

Aircraft X. Location: ZZZ; intersection X and Y; exiting Runway XXR; after the completion of a Part 91; Private IFR flight from ZZZ1 to ZZZ. At approximately XA45; the crew of Aircraft X experienced traffic conflict after exiting Runway XXR at intersection X and Taxiway Y. While on approach; Aircraft X was asked to slow to final approach speed prior to the hand off to ZZZ Tower.After Aircraft X checked in with Tower and received a landing clearance on XXR; an Aircraft Y on approach to XXR; roughly 3 miles ahead of Aircraft X was asked if they could change to XXL. There was another aircraft on the takeoff roll on XXR. The Tower advised the Aircraft Y that they would be doing the Aircraft X behind them 'a favor'. Aircraft X was on the ILS due to haze and had not accepted a visual or called the airport in sight. Aircraft Y commented that the FBO was on the other side of the field and that the XXR was better; but accepted the clearance; side stepped and landed on XXL. Aircraft X landed on XXR and rolled out to intersection X. Aircraft X exited at X and rolled to a stop passed the hold line; at roughly a 45 degree angle; facing North-East in relation to Taxiway Y. Aircraft X was stopped with the brake set and checked in with Ground Control and requested a taxi clearance to Company. ZZZ Ground Controller issued a taxi clearance to Aircraft X; 'Give way to the Aircraft Y south bound on Taxiway Y; then taxi to Company'. Aircraft X acknowledged the clearance and remained in position with the parking brake set. Aircraft Y cleared XXL and was cleared to cross XXR at Intersection Z; and then issued a taxi clearance south bound on Y to Company 1 south of intersection Z and Y. The pilots of Aircraft X then established visual contact with the Aircraft Y taxing at a very high rate of speed southbound on Y. As Aircraft Y got closer; it appeared that contact between the left wing tips of both aircraft was unavoidable. Aircraft Y made no attempt to slow down or correct course to the right. As Aircraft Y went past Aircraft X; the pilots of Aircraft X felt a buffet and left yawing sensation that led them to suspect the wing tips had touched. The crew of Aircraft X reported the contact to ZZZ Ground and requested that the tapes be marked and that an operations vehicle meet the crew at Company.The pilot of Aircraft Y remained silent on the radio; and the ZZZ Ground Controller did not attempt to contact him. Inspection of the Left Winglet on Aircraft X by crew revealed no visible damage. Pilot of Aircraft Y was not at the aircraft when Operations arrived at Company 1. Operations personnel reported no visible damage to the left tip of Aircraft Y. It would appear that Aircraft Y past so close to Aircraft X that the air flow off of the winglet and possibly the propwash buffeted the aircraft. As a precaution; pictures of the winglet were sent and maintenance personnel were consulted; to confirm that no additional actions where necessary.