That's OK. Plenty of people would be very upset to hear it, since it implies that they FF's are goofing off. Nobody cares about the 20 hours of work - its the 1/2 hour of chit-chat that upsets them.
I'm in the electric utility business and its the same here. Lots of coordination and behind the scenes stuff going on. Sometimes, there's lulls in activity as all the pieces of a puzzle are assembled before actually performing the work.