You have to extrapolate it to the end of the season. If Washington won last night, that still had them with the possibility of winning 5 division games and Dallas remaining at only 4 wins.

That's the tiebreaker that matters. If Washington had won, and THEN Dallas, Seattle and Washington all ended up with a 10-6-1 record AND Dallas had a 4-2 division record and Washington had a 5-1-1 division record, Dallas would be eliminated. That is because in a three way tie, in-division team tiebreakers are used to eliminate FIRST.

Before last night, Dallas could lose to Philly, tie with Tennessee, and lose to Washington and then would be eliminated. EXTREMELY small chance, which is why everyone was saying 99% Dallas makes the playoffs, but it wasn't 100% until the Giants picked the ball off in the end zone.