"Bad Weighting" even though model seems perfectly posable?

[Fawfulthegreat64]

So, I ripped a King Bob-Omb model from Mario Golf Super Rush and decided to run it through the new checker tool. The checker decided that my .dae has 54 points with bad weighting, which sounds really bad but even after I double checked, the rig seems perfectly dandy and fine. Moving the leg bones moves the legs, moving the arm bones moves the arms, and so forth. Nothing seems unusually distorted or incorrectly bent. But that doesn't seem like it's enough based on the reply I got about if it would be accepted. They said "either a working rig or no rig" after I already said the rig seemed fine, so it sounds like this is an issue that's completely invisible to me but it completely invalidates the rig for the purposes of this site. So my only option is to post it here as a last resort and ask for help on fixing the issue. The zip can be found here for anyone to take a look at the .dae: https://drive.google.com/file/d/1qsksLT9...sp=sharing

Here is the image of a basic pose I made to show that the rig works:



Personally I still don't see what could be broken about this rig, but if the weighting errors picked up by the detector are that important, I definitely need help fixing them because I am particular about not uploading a character without a rig.