It's not clear he deliberately lied. He plausibly misunderstood a new tool he had recently been introduced to.
Interestingly, it's exactly the same in court! People's lives are put on the line all the time, and lawyers also sometimes flat out lie. This just further indicts the current legal system because it doesn't really "work" but it's just that the mistakes are often covered-up enough until most people forget about them and move on to something else.