Has an NFL game ever ended 10-10?
It has. 10-10 has been a NFL final 24 times in 18,234 games. The first was Chicago Bears and Racine Legion drew on October 12, 1924; the latest was Baltimore Ravens and Philadelphia Eagles drew on November 16, 1997.
That makes 10-10 the 212th most common final score out of 1,095 that have ever occurred in NFL. One point away, 11-10 has happened 2 times and 10-11 has happened never.