I think he's right to an extent. The winless Bucs had the 7-1 Seahawks on the ropes yesterday in Seattle. There is always a chance that any NFL team can beat any other NFL team. Sometimes it's not likely, but it's always possible.
There are definitely bad teams out there. But even the bad ones can jump up and bite you if you're not ready.
Acknowledging this can be both good and bad. On one hand, even mediocre teams feel like they can beat anyone. On the other, it can lead to giving a team a pass for playing down to their competition if they get the win.
I don't think the Seahawks are above questioning after their last two games, even though they won both. And the Cowboys don't get a pass just because they got the win yesterday.