Lloyd Bridges is in this!
Maybe I'm seeing things, but I swear that when Drebin falls through the skylight onto the table in Hapsburg's meeting, it's Lloyd Bridges, not Leslie Nielson, who stands up with dirt and grime all over his face. The shot then changed to Hapsburg, then back to Bridges wiping his face looking down, and then the shot changes again, this time with Nielson straightening his hair.
Then again, maybe I'm just seeing things...