Then it's not P2P... This is where the terms get very muddy and gray.. if the provider is running the network data and servers themselves, then they are a provider.. not exactly the P2P that everyone here is complaining about. -- "Complaining is the least path of resistance for the self-serving, the lazy, and Im told its a womans prerogative..."
It's Both. Their updater does have a primary connection to a direct connection with blizzards FTP downloader. The other 60-70% or so of the connection IS P2P. Hence the problems. Some of those peer to peer connections may download erroneous chunks because of the reset, and therefore the whole download is corrupt.
It does have the ability to dynamically adjust to the lack of P2P ability wether restricted by your ISP or your firewall(s), however this ability is obviously not perfect.