You are most welcome, Gareth.
Mike was nothing if not a complex person.
He was also shrewd enough to know that a forgery confession - any forgery confession of any quality - would immediately be seized upon by the more vocal of those who had been crying "modern hoax", almost from the instant they first heard about his diary, as a complete vindication of their convictions, which is always a nice cuddly warm feeling.
This awareness must have suited his purposes at the time, but when all the confessing was done, and he was back in 'genuine' mode, with Devereux once more the pal who had left him the diary to "do something with", this showed the contempt he had actually felt inside all along for those who threw the most cold water on his baby and denied him his single-handed solving of the mystery of JtR.
It's a tragedy in at least three acts.
"Comedy is simply a funny way of being serious." Peter Ustinov