It world definately be hard to prove it. One would be purchases made while actively playing the game, and if you had an alibi by being at work or something as a parent, and the network/ip used to be purchase it doesnt match the network at work, at least the general area.
Yeah that a good alibi if it was purchased early and you can prove that you've been in the office at that time. What happens if it happen in the evening, and a lot of people are from home so its not a strong argument. Uterine what they'll do in this situation