If it would be my campaign I would not count any post in that thread. Your answer is also wrong from a technical perspective.
I still didnt answer your question, eh?
Yes, its helpful, yes as its helpful it should be considered constructive as you helped to avoid a possible issue in the future for someone else.
I rechecked the signature campaigns rules and only this is mentioned:
"We prefer English posts, no spam, single word posts, single image posts, bumps, +1s will be counted."
Nowhere is mentioned that being helpful is not counted as a constructive post, if there will be mentioned that the post in this thread in this board are not counted then this is another thing. shorena thanks for your post.