One of my friends pointed out that isopropyl alcohol isn't good for people. However, I don't know if you could get hurt by the amount on three pills, and it's plausible that it would have evaporated from the pills fairly quickly.

That was my first thought too. So I looked it up. The stuff isn't good for you but you need a lot to do real harm. And as you say evaporation has worked on the pills already.