I don't think it is a tricky issue. Lots of other countries have "no lies during interrogations" laws and manage just fine.
If a police officer makes an honest mistake then that's fine. But if a police officer is repeatedly stating things during interrogations that they've misunderstood then they're grossly incompetent for whole different reasons than lack of honest character. Just like if a developer kept pushing broken code without any unit tests, you'd have a quiet word with them that they need to put more due diligence into their work.
If a police officer makes an honest mistake then that's fine. But if a police officer is repeatedly stating things during interrogations that they've misunderstood then they're grossly incompetent for whole different reasons than lack of honest character. Just like if a developer kept pushing broken code without any unit tests, you'd have a quiet word with them that they need to put more due diligence into their work.