I'd be so pissed if I ended up prosecuting a case and found out later the cops gave me bunk evidence. Not only is that a huge injustice, it's a waste of time when there are REAL issues to deal with.
But I also am not sure I'd go straight to hanging the prosecutors unless they knew and still charged.
Because while yes, prosecutors should know their cases, at some point folks have to be able to rely on 'experts' (and most prosecutors I've met are... Not great with tech so they are gonna rely on the expertise of others when it comes to this sort of thing).