Not just Edward, oddly, admitted to wearing tiny pants (2,3,5)
I believe the answer is:
in the wrong
'not' is the definition.
I know nothing about this answer so I can't judge whether it can be defined by this definition.
'edward oddly admitted to wearing tiny pants' is the wordplay.
'oddly' indicates alternate letters (letters in odd-numbered positions).
'admitted to' is an insertion indicator.
'wearing' becomes 'in' (as in being 'in' certain clothes).
'tiny pants' becomes 'thong' (type of underwear. I am not sure about the 'tiny' bit.).
The alternating letters of 'edward' are 'ewr'.
'in'+'thong'='inthong'
'ewr' inserted into 'inthong' is 'IN THE WRONG'.
'just' acts as a link.
Can you help me to learn more?
(Other definitions for in the wrong that I've seen before include "At fault" , "Guilty of error" .)