After Freddy Eastwood had cancelled out Dean Morgan's opener for the hosts Steven Craig popped up to head home what proved to be a winner just after half an hour as the home side held on after the break.
Craig's winner - his first for Wycombe and in English football - came from a Max Kretzschmar corner and Brown knows what his side will be focusing on.
"We've been done on a bit of detail yet again," Brown said. "It doesn't matter about all the huffing and puffing and the way we played in the second half.
"Ok, we were camping on their penalty box for much of the game but we've got nothing and that's what the game of football is all about.
"Finish first you're first, and finish second you're second - it's simple facts and we finished second.
"It's about putting your bodies on the line, it's quite simple. We identified set-pieces as a weakness of theirs actually and we thought it could have been their Achilles heel but it turns out it was ours.
"There are certain things you're attached to with set-pieces and one or two have let us down. They will know exactly what to do over the course of the week but it's not about Monday to Friday it's about 90 minutes on a Saturday."