You might want to test it, although it's probably not much harm
unless you mess with it - or not.
Like I said, testing is easy. You may wish to buy the appropriate
respirator - I think the occasional use type is pretty cheap - scrape
a little into a bottle and send to the appropriate authorities.
Like I said, it cost my friend a few minutes of effort and $25, all the
more egregious that this idiot contractor didn't do it.