Sanders said his first-quarter taunting penalty "cost my team," but he added it was also a sign the "league is getting soft."
With the Rams leading 6-0 late in the first quarter Sunday and the Broncos in a second-and-5 situation at the Los Angeles 44-yard line, Broncos quarterback Case Keenum hit Sanders for what Sanders initially believed was a 44-yard touchdown.
As soon as Sanders popped up from a tackle, he pointed a finger in Rams cornerback Troy Hill's face, which drew the flag for taunting.
"To me, honestly, I feel like the league is getting soft," Sanders said. "I'm having fun. I didn't do anything crazy to the guy besides say, 'I got you on that play,' pointing my finger at him. [The official] threw the flag, which is crazy because I feel like I've been in the league nine years and I've been pointing at guys, go back and look at my film, I've been pointing at guys all the time and saying, 'I got you on that play.'
"It was a great throw by Case. I came down with a big play, emotions are high. ... It's not like I walked up to him and head-butted him or something crazy. But it cost my team."
As a touchdown, the penalty would have been assessed on the ensuing kickoff. However, as a scoring play, the play was reviewed with replay, and it was determined Sanders was down at the Rams' 1-yard line.
So the penalty was then tacked on and the ball was moved to the 16-yard line. The Broncos gained only six yards on the next three plays combined and Brandon McManus had to come in for a 28-yard field goal attempt.
It was a play that grew in importance as the afternoon wore on, as the Broncos came back from a 20-3 deficit to make it 23-20 in the final minutes before an onside kick failed.
"There're no moral victories. ... Our guys played hard, that's apparent, but we have to play a better brand of football as far as penalties," Broncos coach Vance Joseph said. "... He knows better, he knows better, I didn't see what happened. ... He can't do that. He knows that."
Said Sanders: "When I look at the scoreboard -- we lost by three points -- I feel like we could have easily punched that ball in, got four [more] points. I don't see the penalty in that. ... I'll learn from it. ... I'll keep chugging along."
The Broncos lost another potential three points in the second quarter because of penalties. Having moved the ball to the Rams' 35-yard line, with the Rams then holding a 13-3 lead, the Broncos had two holding calls in a three-play span to move the ball back to the Denver 35-yard line.
They did not convert a third-and-30 and, instead of a potential field goal attempt, were forced to punt.