Yup, I believe he also admitted to leaving the sample in his car, possibly trunk, while he went to work or did whatever the next day while it was a warm day outside.
Its reported that several other players also tested positive that day, all so freakishly high that they were thrown out but Braun's was barely under the level to be thrown out so he got put through the ringer. Add in that due to testing procedures that the players would have to be absolute morons to be using that day, players then got tested X amount of times regular season so after they hit the last test were free to do anything. And come postseason they had to get tested once(knowing its coming), possibly twice again, and then would be free to do whatever, so if you hadn't hit your last test yet (I think it was 1) you'd have to be a moron to take anything. I'd have my money that at that exact moment Braun's test was a fluke caused by mishandling of sample, just like was assumed with all the other fails that day. It just so happens he was guilty regardless otherwise an innocent person might have had their whole career tainted due to that mishandling.
Also, things like trunk of car while you're not with it, in a basement while sleeping in another part of the house would constitute chain of custody issues.