Weed is soluble in alcohol. It takes a very long time however, and I would really doubt the whiskey would be 'full of' the THC. It takes weeks to make Green Dragon (Alcohol with THC) because the process takes so long for the THC to dissolve into the alcohol. It probably lost a bit of THC, but not too much.

Sounds kinda stupid to me, I'm not sure what kind of effects alcohol has when smoked though.