The problem there is proving it is a ‘gift’ as legally defined by the ATF. On various places on the ATF’s website, they use the ‘gift’ example in regards to a parent or legal guardian, not a third party. Example from this FFL training program.
Remember also that the dealer agreed with this summation when they refused to complete the purchase as well. They felt Kelly was being deceptive in his intentions.
Read the language of the instructions to 11.a. Right there in the example is Mr. Brown using his own money to buy a gun as a gift for Mr. Black. No familial relationship is mentioned, nor required, but third party is specifically mentioned in the instructions. The only issue is whether or not you know, or have reasonable cause to believe the person is prohibited from owning a firearm.