Crew suggested changing leader (7)
I believe the answer is:
gloated
'crew' is the definition.
(as in the past tense of 'crow')
I don't understand how the remainder of the clue works.
(Other definitions for gloated that I've seen before include "Relished maliciously" , "Exulted (over)" , "Triumphed" , "Crowed" .)