This sounds distressingly similar to the Therac-25 failures. A radiotherapy machine who's software was (blindly?) copy-pasted from a previous version of the sys

This sounds distressingly similar to the Therac-25 failures. A radiotherapy machine who's software was (blindly?) copy-pasted from a previous version of the system which had hardware interlocks to prevent unsafe configurations of the radiation emitter. The new one did not have these interlocks, instead doing everything in software. The result of this was a few people being fatally irradiated when a certain race condition was triggered.