Which basically means if you don't agree with the choice/justification you consider it "ignoring continuity." Saying "that character wouldn't do that" doesn't work in comics, if it's in print, it's canon. Period. Meaning THEY WOULD do that. People change, so it's false to say "ten years ago they wouldn't do that"; because people change. Their mentality and priorities and even principles change. Read Pygmalion.
A retcon is contradicting known facts (not motives or opinions), with no justification why it's a contradiction. That is all. Character's acting or thinking differently than they once did is not a retcon.