This is a widely cited counter-example, but I think most linguists think the case is closed regarding whether this is actually a counter-example to the Chomskyian program. Andrew Nevins and David Pesetsky have an extremely convincing rebuttal of Everett's claim.
In βThe Language Instinct,β it's explained why Chomskian mental grammar is likely to be universal, despite isolated counter-examples: pidgin dialects have crappy grammar and are bad at recursion, but children who begin by learning a pidgin from adults, soon develop it into a creole with full-fledged grammar that has all expected features. This happens even when the children speak no other language, e.g. deaf children who learned pieces of a sign language from hearing adults.
