I know several Operative healers and they all said they couldn't do that. He didn't cast a heal and the instant heal is for people below 30%. He was casting an Instant heal all the time on everyone. I have fought some of the best Scoundrel/Op healers, and not a one has ever done that. His Upper hand never went away. If he was to use that instant heal that uses Upper hand then it would go away not refresh, or at least what I have been told.
You can change your build so that you have 40% crit and over 75% Surge and with that you get Upper Hand on almost 50% of your casts. This ensures you never run out of Upper Hand.
For a Sawbones the less Upper Hand you have the less instant casts you have. Emergency Medpack is free.
Now on my Sawbones in PVE I use this build and people are amazed how I can heal but the trick is Upper Hand.
I do not have the PVP gear for this yet but when I get Full WH and re mod that is going to be my build.