When Goku resorts to use Ultra Instinct sign against Gas (chapter 85), so that he does not need to make his heart calm, Gas seems startled at how he looks. He remembers Bardock having a similar aura:
In the flashback fight (chapter 83), Bardock defeated Gas with something similar to UI sign, where he seemed immensly stronger than just a few seconds ago (when he was being beaten up).
So, could Bardock really go Ultra Instinct or is it just a resemblance?
The doubt arises because Bardock's eyes seemed just as normal (when compared to those of Goku in UI):