iphone Reporting Score to Game Center

When reporting scores to Game Center, if the method -reportScoreWithCompletionHandler encounters an error does that开发者_高级运维 necessarily imply the score was not posted? Or are there occasions where the score can be posted but an error was encountered? I'd like to have this clear so that my handling block (which conditions on error being nil or not) can handle this better.

If there is a problem with the posting -> you get an error. If there is no problem -> no error. I'm sure it does imply.