5.4 of the bolt shots make it through the shielding - let's round that down to an even 5. Each one must now contend with the vicious 10AP of the Crisis battlesuit. Which it punches through with ease. Each shot now deals 5 damage. 5 shots have gotten through. 25 damage to 15 wound character, down to -10. Given that this is explosive damage, he probably could've easily died one shot earlier.
You forget that the pilot will only take 20% of the critical damage because of the Battlesuit Critical Damage rule.
Might have misread the rule - the way I read it you still GOT the damage, it's just that the effect was rolled from the table rather than the standard chart. If this IS the case the battlesuit is considerably more durable assuming you don't roll terribly (and even then those +10s from 01-30 will add up eventually).