Watch the entire interview and you will see clearly what he is saying in context, he was discussing a worse case scenario where there is a split between east and west. His actions speak louder then his words, just look at the code. Bitcoin XT will only fork if a seventy five percent consensus is reached, saying anything contrary to this and talking about checkpoints and ignoring the longest chain in regards to Bitcoin XT is really just pure FUD.
i'm a bit confused as to why any "worst case scenario" justifies ignoring the longest valid chain and intentionally breaking bitcoin into multiple blockchains. these are basic, basic defining principles and completely betrays the consensus mechanism outlined in the whitepaper.
the very reason this is a topic of discussion is because everyone possessing basic intelligence knows that 75% (less, including lucky runs) is not sufficient to achieve consensus. basic game theory. consider a 70-30 mining split---the 30% minority that remains on the pre-fork chain have strong incentives to remain there. the biggest incentive is that with 70% of the hashing power mining a different chain, relative hashing power on the pre-fork chain rises by 333%. especially if you are ideologically opposed to the forked chain or believe it is doomed to technical failure. a 75% threshold is so low that by the time the fork happens, we could see miner splits much closer to 70-30, 60-40, 50-50. without a very clear supermajority, this would inevitably break bitcoin in multiple chains forever.
if you're so intent on breaking consensus, just join frapdoc et al and start pushing for a hard fork with only a minority of hashing power. the result is more or less the same. you'd probably just look even more irrelevant than you already do.