Yeah, GP has no idea what they are talking about. They replied something similar on another thread without ever providing evidence for their claims. They even claimed their RC implementation in Haskell is faster than hand-crafted C++.
And your reply game me a chuckle :) The code is unfortunately not open source so I can’t provide the evidence. You believe what you want to believe of course. However I am happy to answer any questions on how it is implemented down to the lowest-level nitty gritty details.