As far as I can tell, the book is badly written fiction with about 30% fact. Whatever else it may be, it's not "the story of the Bovington Tiger".
For example, take the part where the Tiger was actually captured. The book tells us an exciting tale about a British tank sneaking around behind the Tiger, and attacking its crew. Nobody, not the Germans nor the British, have told us that anything like that happened. Where does this tale come from? Supposedly from a man's diary that nobody has seen except for the book's authors!
I carried out my own research into this story. The Tiger was abandoned in a specific place that I identified from photos. As a result I can say that the story is false. It was impossible for a British tank to get behind the Tiger.
David