I dont see what the fuss is about.
If that is an accurate quote, Cooper was praising Justin's record I'd have thought, not speaking bad of him.
Sledging as Why describes it and nothing more.
Apparently Cooper and Edinburgh were close friends so if there was any remark, which is denied, you would think the intention would be to praise Edinburgh. It seems Embleton chucked some chewing gum at Cooper and is trying to mitigate that heinous offence. He could have had his eye out.