I believe OP made a well-intentioned comment in an attempt to prevent the camper from hurting himself or others.
When the comment was blown off, he offered one more polite warning.
When that was also ignored, the OP was courteous and shut his pie hole, as each of us would likely do ;)
Sounds to me like he handled the encounter with courtesy and respect.
I've jumped in and helped a family struggling with their popup roof without being asked (they had a young child trying to hold a corner of a failed lift mechanism). I got a big smile and nod. If not, I would have politely waved and headed back to my own site.
Watch out for your neighbor, offer assistance when you can, and wish them well if they prefer to handle it themselves. Camper's Code.