The upside is that in at least some cases, you can warn the new company and they'll agree to fight the thing - or even preemptively tell the previous company off.
Obviously that's mostly going to work for people with major leverage in the job market, but there have been some notable success stories lately of people not getting sacked.
Obviously that's mostly going to work for people with major leverage in the job market, but there have been some notable success stories lately of people not getting sacked.