I like this. BG had to be home by 5 for dinner. Or maybe 6. So he was expected home daily by that time, right? He worked during the days, or had some other routine that would lead to him returning home around dinner time. He couldn't risk messing up that routine, for alibi purposes.
Yes, that or someone in his household did and was soon to return home from work or college. Maybe this guy works nights and is typically still home at 5-6. Or maybe he’s a college student or unemployed even.