Good Idea, Bad Idea...

So there are holes that are good to have in a bathroom floor, and those that are not so good. To illustrate:

Good Hole:

The hole that the toilet drain comes up through:












Bad Hole:

The one that the HVAC installer put in the floor in front of the toilet for a floor register. Note that, as this was certainly the ideal location for a register, the installer had no hesitation cutting through the floor joist that was in the way.











Thankfully the new subfloor in the bathroom takes care of this opening, but I also need to reinforce the joist below.