Interesting, but log said AP, not Chroniton. What gives?
Also, it was a Capture and Hold match. I was, well, holding one of the outposts by myself, guy uncloaked (alone) from my 2 o'clock and I -with max shields and hull- went poof before I had time to react. There was no one else around and no spam involved of any kind, so I had a good look (and hear) at the aggro: it was cannons.
Please bear with me. I have a fairly decent build, and while I'm not by any means invincible -not by a long shot- I can now put up a good fight for at least a minute before getting whacked. I'm just trying to understand what happened.
Have you asked you enemy what build he used? Might be the simplest way to find out what happened.
Also the chroniton dual beam array does antiproton dmg but the beams have a blue color. Now if you are sure there were no beams involved that doesn't help.
That number is too high for a DHC crit and I can't think of any special consoles/powers that do ap dmg the moment but I will give it some thought.