I find it very hard to believe that anyone significant knew about this at Google. Do you really think that they are in such dire straits that they have to scam Africans for profit?
Months is an incredibly short period of time for a large organization. Especially when considering a small, probably low priority group. A large organization isn't like a startup, for a small low priority group the feedback loop isn't daily, its at best weekly and quite possibly longer even monthly (and gets longer as you go up the corporate ladder). What you may identify about a groups activities in a couple weeks at a small company can easily take months in a large company.
I'm much more certain that they aren't stupid than I am certain that they aren't evil.