It's hard to tell (for me at least...)
I don't know exactly where the sprite is changed but it seems the morph function in bank C2 is only related to the morph status, revert command and morph gauge. Maybe you could trace from there and see what is going on...
The sprite change should be done in bank C2 I think, since the status is toggled there, I haven't seen anything related to the morph status in bank C1 but then again I only had a quick look.
I don't know exactly where the sprite is changed but it seems the morph function in bank C2 is only related to the morph status, revert command and morph gauge. Maybe you could trace from there and see what is going on...
The sprite change should be done in bank C2 I think, since the status is toggled there, I haven't seen anything related to the morph status in bank C1 but then again I only had a quick look.