If he lied, shame on him - and he doesn't deserve to be in law enforcement. The WHY simply doesn't matter. The entire system is corrupted when that happens, no matter the motivation. Justifying the lie this time might benefit you ... next time, it might cause you great harm. One lie almost invariably leads to justification for the next. This is how the system becomes corrupted, or at least perceived as such.
If it was not a lie, but a an articulation of the facts as best he could recall, great. If a knowing and intentional falsehood, then the guy should enter politics - he has smeared the badge.