The rivalry between the Dallas Cowboys and the Washington Redskins goes all the way back to the 1970s, and sometimes extends to non-players.
The person, who uploaded the video, also wrote "At the redskins game and this man got thrown down the steps, LMAOOO."
According to Deadspin.com, two witnesses gave their account of what happened.
The first witness claims the man and his "buddy" were removed earlier in the game by police, but returned about 30 minutes later when the incident occurred.
"I have no idea why they were removed the first time or what sparked the security guard to chuck him down the stairs," added the first witness. "There didn't even appear to be Cowboys fans involved."
The second witness claims the Redskins' fan and a friend were drunk as well as "cussing and yelling." They were told numerous times to pipe down, but continued their antics. Two security guards eventually confronted the men until police escorted them out.
However, the drunken fans returned about 30 minutes later and promised they would be quiet. The security guards spotted them and told them to get up and leave.
One of the security guards was reportedly "irate" and shoved the Redskins fan, causing him to fall down the stairs.