In my opinion, "I owe you a beer" event is the event that we first understand what's in Logan mind all along. It understandable to be the event which give us his 2nd heart. Anyway, this event is kinda RNG since it not 100% to trigger, and if someone has not sleep in the house, there no way triggers this event and easily miss a chance to get the heart.
I think, in the future update, Hyao may add some new event which give us a heart for someone who miss the heart from I owe you a beer event or make this event can trigger even we have his 2nd from Trouble in den event.