What kind of proof can be shown that'll be accepted by most people as proof of a bricked car after an automated software update? No matter what's shown, I can easily think of alternative explanations.
Asking for proof is not complaining. Back in my day, being able to request and see verification of claims was considered a benefit of communicating via internet.
It's literally a complaint so you're wrong, not that there's anything inherently wrong with complaining.
But it's dumb he called the poster on another website a complainer for daring to be upset about his car shutting off. There's no moral superiority for posting (complaining) here rather than there.
Following this logic, everything posted to HN should have someone commenting asking for "proof" because a single article isn't "verified". Do you see how pointless this is?