Given that:
 

 1. According to the white and yellow paper [a block's timestamp must be bigger than the parent's][1].   
 2. According to the white paper a [block's timestamp can be within 15 min of the parent blocktime][2].

Would that imply that if a differential block time of 14 min occurs, 

 1. the next winning miner has to either fake a timestamp, and this potentially could lead to the blockchain running faster and faster into the future,
 3. or wait until his Unix time catches up.

Is this true? [Is there a reason why empirically it never happened][3]?


  [1]: https://ethereum.stackexchange.com/questions/5915/can-a-child-block-have-an-earlier-timestamp-than-the-parent-block
  [2]: http://ethereum.stackexchange.com/a/5926/264
  [3]: https://ethereum.stackexchange.com/questions/5879/what-is-the-measured-distribution-of-block-times-since-homestead