Weird interaction between Pudge rot and Ta refraction

I have no idea if it was intended or not, but earlier in my game, I ganked a Ta mid as a level 2 pudge and my rot was going through her refraction. She was losing her HP, but not her refraction charges, which mean she was keeping her bonus damage and the only way I could break her shield was to right click her. I don't remember it being like that. Tried again in a custom lobby with the friend I was playing with earlier and the interactions were the same.