Craig Gordon has revealed that he was 'wound up' by the linesman during Saturday's clash at Celtic Park.
Hearts travelled to Glasgow to face the almost champions with Robbie Neilson' s side leaving the city with no points after a 4-1 defeat.
The Tynecastle outfit took an early lead through Ellis Simms before Daizen Maeda levelled things up on the half hour mark.
But it was Celtic' s second goal that created a real talking point for the Jambos keeper.
The skipper has revealed that assistant referee Dougie Porter made comments in the tunnel at half-time after the hosts made it 2-1.
Gordon got hand to a Kyogo effort but the shot was deemed over the line.
Potter's decision was to instantly award the Hoops forward a goal, with TV replays proving the linesman correct.
But it was Porter’s attitude following the decision that seems to have rattled the Scottish international.
Speaking to Edinburgh Evening News, Gordon said: “I think it’s about a millimetre over the line [Kyogo’s goal].
"How the linesman from 40 yards away can 100 per cent know that’s over the line, I’m not entirely sure. We’ll have to give him it as a good call.
“He was winding me up coming out for the second half, saying: ‘Good decision, good decision, eh?’ I was like: ‘Oh right, so it’s like that?’ Fair enough, he backed his call. I thought I’d saved it.”
Further goals from Matt O'Riley and a late effort from Giorgos Giakoumakis after he came on from the bench made it a comfortable win for Ange Postecoglou's side.
The three points all but secured the cinch Premiership but with a Rangers victory on Sunday, the Hoops will need to wait before they bring the trophy back to Glasgow's east end.