The return of the balcony of doom

Yesterday I got a call from the super asking if the "restoration" people could work on the balcony some more today. In addition to all the resurfacing done in the fall they are now resurfacing the balcony walls. I was assured that it would only take a couple of hours and not be a problem. The guys doing the work came by just before I left for work (which is a good thing, because rather than leaving a note as I planned, I was able to speak with them and ensure that they are not to be careful of the plexiglass since last time someone "looked" at the balcony $60 worth of plexi was broken). Looking at the cam I can see that they are sill working. It's close to seven hours now since they started. This concerns me. I expect they have probably fouled something up.