Turnstile stopped mid set at The Criterion in Oklahoma City on 5 October while Brendan Yates spoke to the venue's security team. A guard was escorted out, and the band went back to playing. Footage of it is online.
Yates said afterwards that the guard had punched a fan who came over the barricade. Accounts from the floor say the person had been trying to get onto the stage, which at a Turnstile show is less an incident than a feature.
What he said to the room is the part worth quoting. He thanked the security doing a great job at what they were doing, then said there were some who did not get the assignment. He said he knew everyone was coming up there trying to have a good time, that it was high energy and there was movement, and that there was no need for anyone to be swinging on anyone just coming over the barrier. Then the line that ended it: that security guard cannot be here, and the band would not play if he was still there.
He finished by thanking the rest of the team for adjusting and keeping it peaceful. The tour goes on, through Lawrence and St Louis and then into California and Nevada in the middle of the month.