Whether or not there are inaccuracies in this, I am not qualified to say (see C.A.Rollings rather spiteful, self-serving 3* review, in which he also crassly plugs his own book). The Great Escape itself is firmly embedded in British consciousness, due to the iconic Hollywood version. By Hollywood standards, it's actually reasonably accurate (so only mildly inaccurate then!), but this well-written tome paints a rather different picture of an enterprise that has assumed mythical status.
The author's conclusion that the escape was at best pointless, at worst wasteful & counter-productive, is certainly contentious, but on the evidence that he presents, it is equally certainly a valid point of view. Whether it's correct or not is another matter. History, after all, is largely a matter of reading through different viewpoints & trying to sift out for yourself what you think is right. Despite the quibbling of Mr Rollings, the book appears to be well researched; the copious notes, mostly document references, form some 20% of the book. Moreover, the author regularly comments on the dubious nature of some of the documentary evidence he is relying on; especially that of some of the former "Kriegies", who often exagerrate, embellish, and sometimes simply lie. Whatever faults there may be in this book, it is very readable, very interesting, and will surely change your perception of the truth behind the myth.