Played loaner mission vs Deadpool and 2 Thugs. Got Deadpool down to about 800, and left Thugs at 3000. Used Oldest Trick in the Book on higher health Thug. Deadpool intercepted, despite having lower health. Deadpool died. The Thug he defended STILL TOOK DAMAGE, and was left with 300 health. Didn’t break the game, but definitely not working as intended.
Same happens for me. Nice as long as you dont play DP yourself. 
Hey guys, I’ll go ahead and bring with up with the rest of the team and see if we can’t reproduce this. Thanks for taking the time to report the issue!
I just did the loaner mission again and attempted to recreate the error. Took Deadpool down to about 3000 and left a Thug at 3300. I had one CD on the board and used Starlord’s sucker punch, targeting the Thug. Deadpool moved in, and both Deadpool and the Thug took half of the attack’s damage, leaving them at a little over 1000 health a piece. I’ll have to attempt this again tomorrow with a different damaging, targeted power.