Stop it. He needs to go away for a while but it was obviously a mistake.
No, and I'll explain why you (and millions upon millions of others) are wrong.
Mistakes are things we make, errors or lapses in judgements, that have unforseen consequences. You can also toss in minor ignorances and simple oversights.
This is a pattern of behavior that has lead to an eventuality. Self destruction that has sadly also destroyed the life of another with it.
No.... this is not a "mistake". You drank in wild excess, then got behind the wheel of a vehicle. Something he has done for years. Only this time, the numbers game finally reached its finality.
Mistakes are forgivable - this isn't.
When you stop absolving people of awful, often times repeated choices, you'll be shocked at the difference it makes in holding yourself and others accountable.
Kirk should be held to the fullest account the law allows. Sadly the law isn't always synonymous with justice.