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.

http://semantics.uchicago.edu/kennedy/classes/s07/myths/nevi...

https://www.academia.edu/3112859/Evidence_and_argumentation_...

In ‘The Language Instinct,’ 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.