Blue Mountain's Double Down promo: restrictions

[5dark]

Does anyone know how Blue Mountain's the Double Down promo works?

I'm only going for one day and want to split the cost with a friend.
I know it says non-transferable, one use per day but is this enforced (electronically or otherwise) or just a discouragement?

Do they give you two vouchers, where I could just give one to my friend, or will they give you a single voucher they track somehow?

Thanks