Actually it seems to be a somewhat controversial subject among dance critics, even now (in general, there are a lot of debates about the behavior of many writers and artists in France during WWII...)
Lifar fans say that his purpose was to protect the POB, while others say that he was indeed an eager collaborationist (doing far more than what was required) and was interested only in his own interests.
I came across the following book "La vie musicale sous l'occupation"
http://books.google.fr/books?id=qcBpfEu74c8C
which seems to be well documented and is very severe for Lifar (seen as fiercely ambitious and self-serving, mutiplying his salary by more than 8 between 1940 and 1943), it includes (p. 120) an excerpt of a somewhat nauseating letter by Lifar written in 1940 in which he mentions having been antisemitic since his youth, insisting about his own "pure aryan blood"...
Is there an English version?!?!?!