Orphan blocks are a different case than an 2hr shift. When dealing with bitcoin edge cases are very common and sometimes not very well handled. What if half of the miners rejected the block and half accepted the block due to different local times? Then you would have different parts of the network contributing to different forks which is not as cut and dried as an orphan block. It would not be impossible, though highly unlikely.
It's even harder to accomplish because the 2h are relative to the client's current time. As time passes by, a previously rejected block has a higher chance to get accepted.