No need to make assumptions given that they dug into that issue and the problem was algorithmic. As Bob points out that's orthogonal to clean code ideas. If you chose the wrong datastructure or algorithm and have quadratic complexity all the micro-optimizations in the world aren't going to help you.

The only strawman honestly is to pick someone at github writing shoddy code and then using that to argue against system architecture? It's pretty obvious that a text editor lagging on a paragraph of text isn't the consequnce of having wrapped something in a function. If you've written code slower than a human you don't have clean code, you just have bad code.