You do realize that KC game was a gimme sympathy game from the NFL right? Not a single penalty was called on them until late in the game when they had a delay of game (which is an unavoidable call) and they were holding (hell many times they straight up tackled our defenders) like a crack dealer outside a rehab center.
This is actually a very common trend in the NFL after a player dies. Dallas was given the same treatment against Cinci after their team death as well. Somebody actually posted the amount of penalties called on a team after a team tragedy over the past decade and based on the stats... well its definitely not a coincidence. No the NFL doesn't fix the games, but I'm sure they tell the refs to not make any calls they don't need to.
Remember, the NFL is a business first. The feel good story rolls in publicity and $$$.