I'd say the time starts once the undressing happens, so if we chat for 5 mins or so beforehand, then that's ok, and if the end takes a bit longer, then that's ok as well. I usually schedule appts 2 hours apart anyways so as not to feel rushed.
Now, I am not saying it's ok what those two ladies did, but I have had the opposite as well, where a gent purposely draws out the time at the end, and I'm not talking about no 5 or 10 mins either (try 15/20/25 mins, it happened to me once here in London).
And if it's a reg of mine, I have no problem spending longer with them as well.