If there is a discrepancy between the original source when it is *Dragon* or *Dungeon* magazine and the *[Compendium][1]*, which version of the content should be considered the most official?

When answering How many attacks with [Path of the blade ( from Dragon 381)][2] I was surprised that the confusion appears to arise from a slight change to the wording of the power.

  [1]: http://www.wizards.com/dndinsider/compendium/database.aspx
  [2]: https://rpg.stackexchange.com/q/128785/28599