Brown felt his side probably did not deserve to take the Ranfurly Shield from Counties-Manukau, although he was proud his side stayed in the game and made it a contest at the end.
Otago came back with two tries in the final five minutes to give the premiership side a scare before Counties sealed a 29-25 win.
Otago was plagued by mistakes in parts of the match, and Brown did not put the errors down to a lack of skill but more to the toughness of the opposition.
''It was a massive effort to stay in the game, really. We probably made too many mistakes and got beaten up a bit at the breakdowns to win that game,'' Brown said.
''Those errors, they came from the opposition being at just the next level, physical at every contact point and those were where our errors were - just in the contact.
"They brought huge physicality to that game and it is a new experience to our boys.
''To still be in the game at the end and to have the ball was huge from our guys and we probably did not deserve to win it.
"Playing teams that are really physical is something you can not get playing club rugby. You have to go up a level in physicality.
"Counties brings that to a game which is right up to the Super rugby level.
''You just have to fight fire with fire when it comes to the physical contest.
"I think maybe they started to get on top of us at the end of the first half.
"I was happy with the way we started. We were creating what we wanted to create.''
Otago halfback Josh Renton had the ball knocked from his hand when he was millimetres from dotting down after 16 minutes of the first half and that would have given Otago a lead and a healthy dose of confidence.
As it was, Otago rather went into its shell after that and slowly slipped out of the match.
Brown said it was good to at least get a bonus point.
''We stayed pretty composed. Even though we were making mistakes we were still in the game.
"To come back and nearly win showed a bit of what Otago is all about.''
Otago captain Charlie O'Connell agreed with his coach that too many errors and not matching the Counties-Manukau physicality contributed heavily to the defeat.
''We did not match them in physicality in parts of the match. That and unforced errors probably lost us the game,'' O'Connell said.
''There was a lot of turnover ball at ruck time, a lot of dropped ball and a couple of free kicks.
"Stuff like that all mounts up. An opposition can feed off them and get a roll on.''
O'Connell said at the break the team spoke about taking the ball to Counties and not letting the shield holder get on the front foot.
''It was just a case of getting a few more carries and being more aggressive. And accurate as well. We did that in parts of the game and then at the end.''
The cause looked hopeless for Otago with less than 10 minutes to go and the side 13 points down.
But O'Connell knew his team could come back and score some points.
''We were down near the end and I just said we've just got to get our hands on the ball, believe in our structures and play some footy.
"That is what we had to do, and we did it in patches. But we were chasing our tails by then.''
Otago picked up some nasty injuries during the game and there may be forced changes for this Saturday's match against Southland.
Fullback Trent Renata took a heavy knock to the thigh, centre Michael Collins was walking gingerly after the game and loose forward Lee Allan got a head knock early in the second half and left the field.
