I'm not disagreeing with you Vader, btw. I just think that in his situation, he wouldn't have been thinking very clearly and basically instinct kicked in. Destroying evidence isn't really foolproof, I mean, to be perfect about destroying the evidence would've taken days and if he let the kid go, he could've had less than an hour, not to mention if he didn't do it perfectly, they could build a case with the slightest bit of evidence based on what the kid knows.
I guess my conclusion is while he didn't make the right decision, I don't think there was an easily reached right decision whatsoever in this scenario.