Revitalize did damage to me...

After playing a game of Zac with revitalize on ARAM because he heals a lot, I found that its values for amount healed were in the negatives. As it turns out, it is programmed so it increases health costs because it is an ability cast by you that affect your health. By the end of the game, I had a net total healing of -1000 or so. On summoners rift, the values increase your healing whether or not the target is fully healed and applies to the spawn pool. This means that the rune is artificially increasing the values it says healed when, in actuality, it did close to nothing. Thus it misleads you saying it healed for whatever when it could have actually done half that and damaged you more than it healed.