It looked like the classic definition of "The Brady Rule," which prohibits a defensive player from hitting a quarterback below the knees when one or two feet are on the ground. The hit must be above the knee to be legal.
According to CBS Sports, it was ruled that Levy didn't hit him of "his own impetus."
Regarding the hit on Flacco, Ravens coach John Harbaugh said this week he got a different explanation from the referee on the field Monday and the league office Wednesday morning. Levy wasn't penalized in the Ravens' 18-16 win Monday night.
Flacco reportedly sprained his MCL and is wearing a brace on his left knee. He has been limited all week in practice.
There was a fine from that game, but it was Ravens rookie safety Matt Elam who got disciplined. He was fined $7,875 for unnecessary roughness because he "unnecessarily struck the quarterback who slid feet first." Elam was penalized 15 yards in the first quarter for that hit on Lions quarterback Matthew Stafford.