This reminds me of a story on one of my good friends. Years ago he had a similar situation where a suspect was trapped in a bank. He got there and walked up to the drive-up window, stood in front of the window, and watched the guy so he could broadcast a description, etc. The suspect had a handgun and was pacing back and forth trying to figure out what to do, sort of like the guy in this video.
Other officers arrived and they got the guy into custody without incident. My friend told one of the tellers that it was great he could watch the guy, keep everyone updated of what he was doing, and have the cover of the bulletproof glass. The teller told him that the drive up window wasn't bulletproof glass, only the teller cages....
Once it sunk in he'd been exposing himself to a gun wielding suspect while in full uniform and talking on the radio with just a regular sheet of glass between them he went outside and fought off the need to puke.
Theft, armed robbery, use of a firearm while committing a crime...it's only too bad there wasn't a good ricochet in there and he offed himself. Pretty funny episode though.