They're talking about something the size of a boulder according to TFA. Earth gets hit by objects this size all the time.
The diameter of the biggest impactor to hit Earth on any given day is likely to be about 40 centimeters, in a given year about 4 meters, and in a given century about 20 meters.
"There are other elements involved, but if size were the only factor, we'd be looking for an asteroid smaller than about 40 feet (12 meters) across," said Paul Chodas, a senior scientist in the Near-Earth Object Program Office at NASA's Jet Propulsion Laboratory
- Most software projects are reasearch and development; buiding something new that's never been built before; hence there's a lot of risk. It's not like a wall that people have been building the same kind of wall for thousands of years. Risk costs money. The only question is who's going to pay for it. Hint: the boss, unless you're stupid, or you have some sort of equity you want to protect.
- If you're an employee, the boss has two choices; pay you to fix it, or fire you. Construction and programming are the same in this regard. Maybe he can take it out of your salary, I dunno, might depend on emplyment terms or state law. But typically he cannot compel you to work for free; that's called slavery.
- If you're on contract, you're only obligated to fix your mistakes to the extent that the warranty clause demands it. No warranty clause no fixie. The boss may be able to terminate the contract or just not contract with you again, his choice. Your choice if you want his buisness bad enough to fix it for free. Again, construction and programming are the same in this regard. If you do have a warranty clause you will typically bake your own cost of fixing your own bugs into your bid and or hourly rate so it's still not really free for the Boss, your bugs still cost him money.