Daniel Dove told the court he complied with the police up until the point he felt he was being humiliated.
"I felt embarrassed, he said. "I flicked my pants at him because I was annoyed at what he had done.
"I didn't know he (PC Birch) had a taser. He pulled it from behind his back and shot me with it. I think it was unrational (sic) to use it."
Under cross-examination Mr Dove denied being abusive and threatening club door staff. He also refuted kneeing a police officer in the groin during his arrest.
More top news
One in six roads in the region are today revealed to be in such poor condition they will last just five more years before falling apart.
A decision on a new sentence means the former Royal Marine will be "freed from prison" within two weeks.
Cornish MP George Eustice says badgers could be infected with "something like a herpes virus" to stop them spreading bovine TB to cows.