Unfortunately, the fact that it is intentional or not does not make it criminal or not (quote from Spain's currnet Criminal and Procedural Air Navigation Law)
When there is death or serious injury as a result of lack of skills or professional negligence, the penalties mentioned in this article will be imposed to their greatest extent. Those penalties may be additionally increased by one or two levels, depending on the case, if, in the opinion of the Court, the damage caused were extremely serious and should also apply in addition to the penalty of loss of professional or aeronautical licenses. In no event shall the Court impose punishment that proves equal to or higher than that corresponding to the same offence when wilful.
The difference is only one or two levels in severity of the punishment. For example, for 100 fatalities: 100x10 yrs=1000yrs vs 100x5yrs=500yrs. In both cases, the actual time in prison will be 10 to (the maximum) 30 years depending on redemptions...result: no difference.
That's the way it is in our criminal system.