According to this Stack Exchange post from last year a full IPv4 routing table requires on the order of a few hundred MBs of RAM. This is indeed a tiny fraction of the cost of maintaining the global internet infrastructure.
No. A network like Facebook's is vast and complicated and managed by higher-level configuration systems, not people emailing patches around.
If this issue is even to do with BGP it's much more likely the root of the problem is somewhere in this configuration system and that fixing it is compounded by some other issues that nobody foresaw. Huge events like this are always a perfect storm of several factors, any one or two of which would be a total noop alone.
https://networkengineering.stackexchange.com/questions/76562...