At least with Codex, this has not been my experience at all. It still screws up sure, but in every case I can ask "why did you do this" and it can trace back what made it take that particular decision. Typically it's always that I either didn't specify the problem correctly or made a really dumb mistake (executing the task on the wrong project....did this one yesterday) or it's something within a skill file that instructs it (at which point I fixup the instructions).
Once in a blue moon it's actually the model making a material error in it's thinking and I have to go back and redo it.
Once in a blue moon it's actually the model making a material error in it's thinking and I have to go back and redo it.