You're right, of course. Yes, it may well be unreasonable for the police to wait only five seconds or so after knocking before starting to bash your door in. Especially when it's 6:30 a.m. Not many people are going to get to the door within five seconds at 6:30 in the morning. Ain't gonna happen.
But a jury found the other way. And that's plausible. Maybe the search wasn't reasonable. But maybe it was. You gotta defer to the jury on this one, which found the latter. Right or wrong.
