The problem is that he didn't really do anything that they can prove...
As long as they can't show/proof that his (natural) levels dropped due to an illegal substance, I don't think it's worth speculating.
You could even argue that he is almost following the normal required action (something of 8 days not racing), since he rode only about 20 min before stepping out of the race (and I am assuming he won't ride much else before the Tour).
(Although the start of this thread should be kicking off at least a weeks discussion now and some future back-references to this item when Rolland - who again hasn't shown much during the year - will be top 10 in the Tour again
)