Manager Jack Wilshere was sent off and had to endure Luton slipping to a 2-1 loss away at Stevenage from the dressing room.
The flashpoint came after 23 minutes when Dan Kemp burst on to a free ball and guided a lovely effort past Josh Keeley to open the scoring for Stevenage.
The Luton bench were incensed that there was no foul given on Liam Walsh by Dan Phillips during the build-up, and whatever Wilshere said in response was deemed unacceptable by referee Andrew Humphries.
Bookings followed on both sides as passions rose and there were almost more discipline problems when a long Lewis Freestone clearance went over the heads of the Luton defence and then bounced over Keeley who had advanced from his area.
Kemp got in but ended up on the turf before he had a chance to shoot. No push was the decision this time.