Kog'maw Q recall Bug

I was playing Kog'maw and was taking scuttle, and it was at one hit, and so I q'd then immediately recalled as it was casting, and it took the mana and put it on cooldown, but the spell didn't do anything. The weird snot thing didn't shoot out, and it did no damage. When I tried to do it again (many times) though, it worked just fine, so I don't know if it's really an issue.