What does this mean? "But if rigorous analysis escapes Marrs, little else does."

The sentence is from the following extract:

Marrs shows little discrimination, overemphasizing dubious phenomena like remote viewing and crop circles, and giving nearly equal weight to ludicrous pretenders like Billy Meier (who claimed close encounter with Pleiadians) and sophisticated commentators like Jacques Vallée. Marrs even devotes a chapter to theories that the moon may be a UFO, and he refuses to rule out obvious frauds like the alien autopsy tapes. But if rigorous analysis escapes Marrs, little else does; this is the most entertaining and complete overview of flying saucers and their crew in years.

https://en.wikipedia.org/wiki/Jim_Marrs

Can someone explain what the bolded sentence means? Thanks!

Per the OED, escape can take on the meaning of elude, so when anything escapes someone, that thing has eluded their observation, attempt, search, notice, or recollection.

Therefore Marrs failed at rigorous analysis. It was beyond him. It had eluded him.

The person used as the object here in the transitive verb may originally have been in the dative case when English still had one. The Latinists would have classified this use as a “dative of separation”. But by the time Middle English borrowed the word from French, where it was only ever intransitive, the dative case for indirect objects and accusative case for direct objects had already converged, and were soon to be lost altogether. (Words like him were originally dative only and never accusative in English, but now we use them for any object.)

To quote the OED on this:

In French the verb échapper has always remained intransitive. The development of the transitive senses in English was assisted by the formal coincidence of the dative and the accusative; compare also such constructions as ‘to be banished the country’. Formerly the verb was often conjugated with be, not only when intransitive (as still sometimes archaic) but also when transitive.

Under the sense whose examples include No word of courtesy escaped his lips, they have this further related note:

Perhaps the object was originally dative, in which case this use belongs historically to sense 1. Cf. French il lui est échappé une sottise.