Earlier quoted context omitted.
What language can be better peer-reviewed?
A purely functional statically typed one, like OCaml or Haskell, because there would be so much less to review, and an insane amount of the reviewing work is automatic. Zero bugs around state, zero bugs around memory mgmt, zero bugs about error conditions not being handled, zero bugs due to some data being expected but not being written, etc.
The programmer admitted that he was a cryptography novice, and in fact a Haskell novice.
As a result the code he wrote is needlessly abstract - for one thing the guy uses Free monads and in turn ropes in template Haskell as part of his state model. I really have no idea what code he's generating.
The code has other features that make review challenging - for instance he doesn't qualify any of his imports so it's hard to tell where to look for the functions he's implementing.
Maybe you are better at auditing Haskell than I am. As DJ Bernstein writes in various places, one common exploit is to construct an elliptic curve Diffie Helman shared secret with input that isn't a curve point. I really can't tell if the guy is mitigating against this attack or not, but here you can have a look: