From what i've seen of A/G (I won't say where) it is a farse. Utterly pointless and totally useless.
In this instance the A/G was being operated while the phone was being answered and customers being served...by the same person.
I, for one, think at airfields without ATC a unicom system as in the US is far safer allowing pilots to warn each other where they are rather than have to do it through a complicating middle-man.