I didn't realize Floyd had only thrown 22. I guess he probably could have had another inning in him. I don't necessarily think this is on Gibbons, though. Tepera would have eventually been needed if the offense continued to struggle. He'd eventually have been needed for a save even if they managed to put a run up. I guess one could argue that Floyd was better off facing the top of the order, but Tepera would eventually have had to come in. I honestly don't think this move was egregious. At worst, maybe slightly premature.
Gibby was on his last option and would, at best, have very shortly needed to pull the trigger anyway. Plus if Tepera is as good against lefties as they claim his skillset to be, it's not unreasonable for him to face Belt, Span, Panik, etc. Arnold Leon coming out of nowhere vs. Steven Souza this is not, IMO.