Anakin still has damage reduction after heroic might

https://answers.ea.com/t5/Bug-Reports/Anakin-retains-90-Damage-Reduction-even-after-Heroic-Might-has/m-p/7589343#M21768

However, I'm unsure if it's due to Heroic Might or Retribution. In your clip it seems he's already with 90% damage reduction before using HM. Anyway, every skill which grants these abusive damage reduction values has a BUG which the resistance lingers after it should have ended. I believe Obi's got fixed for good, but we never know.

He was using HM when the video started. I didn't show him start the animation

You're correct, I've seen the releasing animation and thought it was the starting one. Nonetheless, I still don't know if HM can trigger this, although it may. Are you sure he didn't use retribution before? I've seen this 90% dmg reduction being triggered by Retribution without a doubt, and it can linger for quite a while, maybe even up to 10 seconds. But with HM I never experienced a situation where I could clearly see HM was the culprit.

Anyway, DICE is known to do things up in steps. They got rid of Obi's lingering dmg reduction, but not Anakin's, and now they included Vader to the pool. Maybe in a year they'll have this fixed, just like it took a year and a half for them to fix one Block BUG, the one I called Disabled Block BUG. Let's hope not.

Credit given where credit is due, they've been bugfixing a lot more in 2019 up to now then what they've done through the whole of 2018. Let us hope they get this soon.