I have noticed some health desync issues the last few times I've fought Na'Ruzz (north elsweyr world boss). I finally took a snapshot for proof. A group of 5 of us killed him for the quest, and I ended the fight with 43% health. I mounted up, rode back to the Stitches wayshrine, ported to Rimmen, and walked over to the crafting area to do my dailies. I'm STILL at 43% health.

I picked up, crafted, and turned in my crafting dailies, and turned my world boss daily (still at 43%), and ported to Tideholm. Then my health finally reset to 100% once I was on a different map entirely.
This is PC/NA.
(Also, note the outlandish ping from Greeley, Colorado. It was up and down from 100-ish to 999+ all last night. But this desync happens even when ping is "normal".)