When Cap’s shield only does 600 damage.
What?
Oh crap, I brought the wrong Cap to this fight - the 2* instead of the boosted 3*.
.<
I’ve definitely taken my LR tank team into fights with 180 goons before. It’s painful, but I think to myself, hey, this humiliating defeat will hopefully help with my scaling.
Building and building yellow to fill up my green meter. Finally get to 12. Thunder strike highest health target and…
723 damage…
Whoops, didn’t mean to bring PeeWee Thor to this fight.
That feeling when I press fight too quickly before resetting my boosters from previous fight.
This has happened to me so many times when I was still naive and grinded the first prologue mission for 20-iso. 
Also happened to me once when both my Caps were level 45. Made sure that it didn’t happen again by checking for Steve Roger’s blonde hair.