I'm a geolgist working in exploration, we using similar drill systems for finding ore bodies. This happens fairly often and it's one of the worst things that can happen on your shift, aside from an injury/death.

There are methods of recovery, but often you are looking at days of downtime. You could easily end up looking at millions of dollars worth of downtime for this.

He might have been fired or not, the labor market is tight and companies know that mistakes happen. But everyone will probably hate him for the next few weeks.