Kinda inspired by all the earthquake news since the Tsar bomb itself cause a fairly large one for man made objects. Yes this probably is fairly ASB. But then again you should never underestimate human stupidity.
So what if for some reason they decided not to use that lead tamper to halve the yield whether it be arrogance, bureaucratic ineptitude, or maybe they just found a better parachute to give the pilot more time to get away? How much would this screw up the far north and affect the nuclear arms race?