I'm trying to understand why in this sentence from a book I'm reading the past perfect is used instead of the present perfect:
For a long moment he thought he had gone too far.
For a long moment he thought he have gone too far.
CGEL has these examples in Chapter 3:
He was believed to have written it the previous week
At that time I had written four chapters.
In both, the perfect locates the writing as anterior to some To which is identified via other features of the sentence as anterior to Td
In my example, why is 'he thought' not enough to locate the To in the past without using the preterite perfect? Thanks.