I'm not so sure. If you wanted to be deliberate, you'd choose a plausible value that you could control.

No one is going to suspect `98761316832165974216498789746` is anything other than random. But `000000000000000123` looks suspicious.

Makes no sense.

If it was deliberate, one would use keys that only the person abusing it has. Not keys everyone can guess if they get a hint.

Why would it be?

Sounds more like extremely sloppy procedures. Which depressingly I doubt are unusual among CAs.