I don't recall what it was ... I want to say a false start? Offside? Some penalty against Minnesota, and the lead official seemed genuinely disappointed announcing it, especially compared to his tone on other calls.
A league of the NFL's stature is worthy of much, much better officiating than most of these buffoons. There are what ... 1, maybe 2, consistently high quality, professional, engaged, well-studied and well-prepared officiating crews in the NFL. A lot of NCAA games have better officials from what I see.
Most of these crews remind of what the replacement officials looked like during the 2012 season. There was a noticeable drop-off in the quality of officiating to the extent that it forced the NFL's hand to negotiate and bring back the usual guys. Once they were back, the quality of officiating improved. Now, the status quo is replacement ref quality.
Not that officiating in the NFL was ever perfect but I do recall it being consistently better, across the board, pre-2016 or so. This development of really atrocious officiating in a relatively recent development.
I hope the NFL does something to overhaul, revamp, and improve their officiating program.