You seem to be confusing me shooting his gun with purchasing his gun. You are quite mistaken about the "felony". UBCs are about PURCHASING a firearm, not shooting someone else's gun WITH their permission and under their supervision. Comparisions to Lanza fall flat as he clearly didn't have permission to shoot his mothers guns.
TimB, the proposed UBC covers the TRANSFER of a gun. What your friend did was against the proposed law.
If it was only about buying a gun you could get around it by giving or loaning a gun to some one. The law prevents that. What your friend did would be illegal.