The NFC East side took an early lead in the game, but their opponents levelled in the third quarter, before edging ahead late on to win 34-27.
The Redskins quarterback told reporters: "It felt like we were in control, and when you walk off the field with a loss, it's very disheartening, but I don't think anyone on this team is going to quit."
Linebacker Brian Orakpo added: "We can't let a team like that score that many points. It's totally on us. We were sleepwalking at times."
The result leaves Washington third in their division with a 3-5 record.