This is something I get after coworkers about, although usually in larger sizes because the connector is not gripping the armor.
I agree with Think Good here.
Either they had no antishort bushing and used tape in place of it or they had an antishort bushing and needed tape to hold it in place due to the use of a NM connector.
When I tell coworkers not to do this they always will tell me that MC armor is not a grounding conductor and that the box is grounded by the insulated grounding conductor in the MC.
What they seem to overlook is that the armor is a metal raceway that needs to be bonded/grounded.