Clerical for an hour, /maybe/. Not clerical for nine hours, that's planning.
Any tech they seized is now being foresically analysed. He is unlikely to get it back.
They probably thought that it was highly likely he was a data mule between Greenwald and Poitras. I'd guess that they were probably right in that assumption.
I know a man, who knows a dog. I'll leave it at that.
If you're right, they screwed up, because they detained him on his trip back to Brazil. Any data he might have been carrying to Poitras he could have already delivered -- and I'm sure he would have been smart enough not to keep a copy.