Eh kind of... The author was talking about a current iteration of the Rust code being suboptimal, not the current one, which the author believed was well-optimized.

> The objective is to get the fastest implementation possible, and having optimised Java and Rust implementations to compare against is a motivator to keep going until there really isn’t anything else that can be tried!

> Do you think Common Lisp can run as fast as well-optimised Rust? Read on if you want to find out.