I opened it up and checked things. The issue is that metal 'tab' indicated in the video. Though it isn't out of place in my case. It just is refusing to slide up and over the contour of the plastic master switch lever. Instead, it appears to have too much friction and is just pushing straight back on the metal tab instead of riding up and over the bump on the lever. If I slide a screwdriver under the metal tab and lift it slightly the lever moves fine. So I applied some silicone lube to the contact area between the metal tab and switch lever. That seems to have done the trick for now. This saw isn't old or dirty so I don't think that is the cause. And my dad, who originally purchased it, never had any switch issues. Just my luck, I guess.
Thanks for the tips!