Why would you even tempt fate by ordering a "virgin" drink for your child?
This is starting to really bother me now. This article from Consumerist (http://consumerist.com/2012/05/the-alcohol-free-part-of-a-daquiri-order-for-4-year-olds-is-the-key-phrase.html) links to THREE other articles where a similar thing happened.
If the prevalence of kids being accidentally served alcholic "slushies" is so high, why would you even bother ordering one? Why do parents not realize that the drinks are intended to be alcoholic and either A) not order them for their child, B) double-check when the drink arrives to make sure it was made without alcohol, or C) test it out themselves first.
It seems like the sort of absentee parentism that is crazy prevalent these days. Don't actually be responsible, just blame someone else when an HONEST mistake is made.