Anonymous Twitter sources may have _low_ credibility, but Elon musk has _exactly zero_ credibility at this point. He has a significant and proven track record of making false and misleading statements, even ignoring the many many more difficult to prove allegations.

In my personal experience, software engineers, when you ask them about technical matters like "does the code do X" or "is there a condition for Y" are generally pretty honest. Programming is a task that requires being able to have structured and literal reasoning, and asking engineers about purely technical details usually triggers that response, even if you can imagine a social motive for lying.