Its obvious that with your trained eyes and experience you can spot mistakes which others either cant or do see but choose not to point out. To improve, knowing ones mistake is part of the learning process.
In this particular image, I am curious to know why you attribute the faint colour marks on the back (I admit I did not notice them before reading your comment) to post processing gone wrong. Use of which tool/s in wrong measure would introduce such a effect/result.
I checked whether a little egret can have such colour tinge in any season or stage of development and did not find any such mention. So obviously you seem to be right. I just want to understand how you came to that conclusion.