Just a few weeks ago I heard a member of staff swearing, it was hard to miss. I quietly and politely highlighted the fact he'd let the 'F' bomb slip and had a little laugh about it. He was very apologetic even though I told him it didn't bother me. I just didn't want him to make the same mistake again and someone else who hears him take it further. I think he probably thought a bit more about the words he chose for the rest of that week.
Ultimately, staff are human and slip up. I don't think minor mistakes like that are a problem really, as long as it wasn't directed at someone in a malicious manner. I'm sure some staff would appreciate a pointer or quiet word if you had a problem, rather than complaining to a higher body and them being ripped into for something that was only a minor mistake.