When Larry is talking to Hank in Hank's office, the boom mic can be seen in the mirror.
When Larry is talking to Hank in Hank's office about Hank's negotiations with the network, a boom mic is clearly visible in the mirror directly behind Larry. In the first two shots, there is some sort of video manipulation to try to cover up the boom mic.
During a commercial break of the show when Robin Williams is a guest, Larry and Hank start trading verbal barbs, with Williams in between. At one point, Robin Williams turns to Larry and calls him "Garry", for Garry Shandling.