It's in no way a fear of firing someone that's little easy. The fear is the weeks/months of issues before someone is fired. Further, many people that are part of the process will be working with this person, but not be able to fire them.
> Is there also a fear of three people doing the work of four for weeks/months since there's the possibility someone could be a bad hire?
Apparently not at my employer. My team was 10 people 4 years ago, and we're down to 6 now, without much dip in workload. We had someone leave about a month ago, and we're still fighting to get a job rec to replace that person.