That's really weird. That really sounds like a nuke snuck up on you or a nuke's AOE got you and stuff around it (nukes have big AOEs).
I really should just eliminate Daggers from those fleets, anyhow; those are supposed to be newbie-friendly encounters, not "OMG I'm dead" encounters. Will fix, same with the Pirates and their !@#!@! Boarding Shuttles, lol.
Anyhow, the critical explosion code has now been changed and I'll test it a bit.
Explosion radius is now 2X collision size of the ship (down from 3), measured from the collision radii of the two ships involved (IOW, if the exploding ship's radius is 100 and your ship's collision radius edge is 299 units away, you're hit, if you're 301 units away, you're fine). Generally speaking, that means that only the very largest ships will cause a lot of hits to things around them (a typical Destroyer has a radius of about 100, and 300 range is practically point-blank).
This should both greatly improve hits for the big guys going critical (which was definitely intended) and it's a nerf for fighter explosions (unless they detonate right overhead, in which case they'll generate a hit for sure now, like they should).