DDOS is different from crashing.

And I doubt Facebook implemented something that actually saturates the network, usually a scraper implements a limit on concurrent connections and often also a delay between connections (e.g. max 10 concurrent, 100ms delay).

Chances are the website operator implemented a webserver with terrible RAM efficiency that runs out of RAM and crashes after 10 concurrent requests, or that saturates the CPU from simple requests, or something like that.

You can doubt all you want, but none of us really know, so maybe you could consider interpreting people's posts a bit more generously in 2025.

I've seen concurrency in excess of 500 from Metas crawlers to a single site. That site had just moved all their images so all the requests hit the "pretty url" rewrite into a slow dynamic request handler. It did not go very well.