I put an absorb bulb on my delta Sunflora during the whirl island Audrey battle, so I could try and burn her Swampert with it and not worry about getting hit by an inevitable water attack. But instead of absorbing the Waterfall it used on me, it just completely ignored it and hit my Sunflora anyway.
It’s (I believe) a common misconception of the item. It doesn’t negate damage, the user has to survive to receive the boost. If Sunflora survived and it didn’t received the boost then it’s possibly bugged. This goes for Cell Battery too.