Well i think the responsible thing to do about his comments would be to investigate it - if his comments are accurate, it needs to be assessed how such a breach in security could occur and how can it be rectified ( for if it can happen in India, it can happen anywhere in the cricket world - india has one of the highest security standards in cricket, as much as the Anglo-corridor here would think otherwise due to tabloid journalism).
If his comments are shown to be a false publicity gimmick, he should be heavily sanctioned for such an irresponsible statement.
As per the 'other' side of the coin, i can see a motivation- the quintessential 'shock value uproar to raise the publicity and thus desirability of yer product'. Its been happening for ages in Hollywood and some american sportsmen are known to paint a picture of ' me vs the world, i had to fight every step of the way, right from my mommy's womb'.
Flintoff probably figures that at most this would lead to a few tests banned or a heavy fine. If his comments pick up steam, the gain in sales ( and thus royalty $$) could more than cover his fine and he's young- a few tests wouldnt mean anything to him at this stage. Either way, its unlikely that it would be anything more than civil litigation instead of a criminal one ( even if Delhi Police chooses to persue it to the hilt) and if money is the motivation, it is a calculated gamble - not only is it likely that such a shocking story to give a significant boost to his book, it is likely that he would become an even bigger heart-throb of the English populace and thus spin even more money. ( given that the English culture loves 'me vs the world and i won'/' i was kicked, shot, bounced, knifed but i still got up and conquered the world' plot-lines)