HuntinMN,
Unless your dad laid out specific guidlines for the hunter as far as what he could and could not shoot on your property you have no reason to be upset at his choice to shoot that deer.......Wounding him is unfortunate and never a pleasant thought, but as soon as you give someone permission to hunt without a set of rules, the deer now become "His" to make his own decisions with.
If that was a problem I suggest you mention to your dad to lay down some ground rules for guest hunters if you want certain deer off limits, especially since you say he has plans to continue hunting there.