It's pretty easy to do that at various times during the lounge's operating hours as it seems like the one or two people who are assigned to staff the lounge check-in desk at any given point of time are also to do other duties that require them to leave the desk from time to time. [Or maybe they are taking coffee/smoking breaks?]

AY's primary long-haul lounge entrance is left unguarded more often than any other airline's primary long-haul lounge entrance at its own hub that I've ever visited.