Dude, if you let someone get out of combat for a full drink in an arena match, bad things happen. This has always been the case. Anyone who drops combat for the nine seconds it takes to soul harvest is going to be able to get their full resource bar back. Letting people drop combat is 1500-bracket gameplay.
Here's a thought: park your healer at his portal to tag him with a judgment each time he ports. Then rinse/repeat chasing him up/down until HOJ is off cooldown. Then kill him.