4* Thor TU, charged yellow tile didn't heal wolverine

I was playing today when the AI used a 4* Thor Team Up attack creating charged tiles. My Astonishing X-men Wolverine was at about 1500 health (below 50%) and I made a yellow match using that charged tile and it did not heal him. Since this seldom comes up, it isn't something i can duplicate easily.

Has anyone else experienced this? I don't even know if it's ticket worthy.