What is and isn’t a “lowering the helmet” foul? Nobody seems to know.

There was a startling disparity of standard in the early and late Sunday games when it came to the lowering the helmet foul.

With 1:42 left in the first half of the Chiefs’ 22-17 divisional round win over the Browns, Browns receiver Rashard Higgins fumbled the ball into the end zone after catching a deep pass from Baker Mayfield. Helping to cause the fumble was Chiefs safety Daniel Sorensen, who clearly led with his helmet on the play.

The ruling on the field was a touchback for the Chiefs, and since the no-call for lowering the head to initiate contact isn’t reviewable, the right result didn’t happen. The right result would have been for the Browns to have the ball with first-and-goal from the Kansas City one-yard line. Given the final score, this non-call could have cost the Browns a trip to the AFC Championship game.

We’re thinking that the league may have sent a memo to Shawn Hochuli’s crew after Clay Martin’s crew blew it in the early game. With 12:45 left in the first quarter of the Saints-Buccaneers divisional round game, Bucs safety Jordan Whitehead was flagged for lowering the head to initiate contact on a hit to Saints receiver Emmanuel Sanders that was far less conclusive.

One notable Browns fan was unimpressed by the disparity.

NBC rules analyst and former official Terry McAulay explained the problems with the rule that has led to so much inconsistency.

Given the stakes involved, perhaps the league should develop some patience.