ijph,
If it's anytime you are being let out early it matters if it matters to them. Not sure why you keep missing that point.
No, it doesn't always matter, especially if it's only a few minutes. Again, him going to the bar after his shift would've already been over is inconsequential. It's pretty stupid to think that someone would leave a whole quarter of an hour early just to go out and get the party started at 2:45 PM, especially if they showed no tendency for such behavior in the past (which we can't honestly speak of in this case).
On a separate note, whoever ratted him out is a douchebag and a half and there's no reason to work with people like that, or his boss that isn't understanding of the situation at hand, especially for a longtime and loyal employee. They were not showing him the same loyalty he showed them, and should consider themselves lucky he's even giving two weeks.
EDIT: If Silence had a history of leaving early, then yeah, this played out as it would pretty much anywhere.