It was a close call.
I can understand why it was ruled a fumble. Yes, he was down by contact, but probably for less than a second, and the ball came out after his knee was down, but he was not flat on the ground. If you were on the field during the play, not sure you would have had the benefit of multiple angles of super slow motion. Thankfully it was reviewed and the right call made.
After frustrating games here, I have seen plenty of us grumble about incompetent officiating. Go back and check the Bills post game thread, or the Jets play-off loss. We don't have quite the emotional investment a player does. It's great when players say that one call didn't change the outcome, and they have to play better. It's hard to blame them when they occasionally spout off like we do. It's strange to see people find this 'hilarious' when there's so much of that from our end, pointing out holding on Revis or against Hernandez. "They hit Brady's head!" "They held Wilfork!" "That was never pass interference!" Nature of the game, I think.