It’s hard to know what will trigger genuine fear in a rabbit, but my first guess was that it may have seemed like he was a predator, not just a person she knows. A bunny will not always recognize someone if their silhouette changes, like they wear a big hat for example. And any time you gesture in a way that resembles a predator you can cause fear. That means, hands descending from above, fingers splayed, can look like claws to a bunny. He may have shooed her by using his hands swooping in wide, from above, and scared her without even touching her much. With you, her protector, out of the room, it could have made a difference.
Having him around, ignoring her and feeding her treats is definitely the way to start repairs. Have him only come up to her with palms up, hands low, to gently stroke her nose and nothing else for a while. Hiding a treat in his had while lying on the floor may give her the courage to sniff around him again. But you are Ashe’s person, not his, so there may be a bit of rivalry anyway.