Overall, the data lines up with my own intuition, but I thought I might throw my own interpretation into the ring.

One of the biggest keys to doing well on technical interviews is to completely separate the problem solving from the coding. The strongest interviewers will discuss the problem and solve it at an abstract level using diagrams. Once satisfied with the solution, they'll code the entire thing making few mistakes.

I think this is what drives most of those metrics. Strong interviewers submit code later, and have a higher chance of it being correct because they take the time to problem solve upfront. Their thought process seems more clear because there isn't the iteration of "this should work, let me code it, oh no wait, that's wrong, let me erase this now..."