Bodacious expert providing strong proof? (7,3)
I believe the answer is:
smoking gun
'strong proof?' is the definition.
(I've seen this in another clue)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for smoking gun that I've seen before include "Piece of incriminating evidence" , "Strong circumstantial evidence" , "Immediate and irrefutable evidence of crime" , "Clear evidence" , "Weapon evidently just used" .)