I've long believed that a large part of technological evil comes from bugs which were introduced innocuously, but intentionally not fixed.
Like, your ISP wouldn't intentionally design a system to steal your money, but they would build a low-quality billing system and then prioritise fixing systematic bugs that cause errors in the customer's favour, while leaving the ones that cause overbilling.
This could easily be the same on Facebook - this got swept up in a false positive and then someone decided it's not a good one to fix.