What is your evidence that it was haphazard?

The fact that they're starting to realize their fuckup (among many other reasons such as not giving advanced warning as so legally required etc).

https://twitter.com/CaseyNewton/status/1589075543420325888

So by your definition, a fuckup is when something isn't done absolutely perfectly? Let's be realistic for a moment here; surely it would be WAY more remarkable if a company laid off 3,700 employees and exactly zero mistakes were made.

What level of error would be sufficient to warrant the haphazard descriptor? Two percent? One percent?

A company like Twitter is complex, and it's very likely that some number of people are important in a way which cannot be seen from a top-down view. Hence error correction. It's a good thing. I see it as a healthy sign that Twitter management are identifying and rectifying their mistakes so quickly.