What the OP did is certainly NOT a straw purchase in Minnesota or anywhere else in the US. Many folks will argue that it is, they are wrong. You will even have FFLs argue the point, they are wrong as well. I believe the definition is right on the back of the 4473 even. Buying the firearm as a gift for a person who would otherwise be able to purchase it themselves and legally possess it IS NOT a straw purchase under federal law.
"A Liberal is someone who doesn't care what you do, as long as it's mandatory". - Charles Krauthammer