...which put paid to my cunning plan for killing Tvericus without taking damage! At least it kept the zombies off for a bit.
Sorry, I never thought to take a screenshot. I am pretty certain, though, that one of the Wall Of Stone squares was adjacent to one of Tvericus's four squares, and that he nevertheless made a successful melee attack from that position. [If a flag is set at the start of your turn when you are beside a blocking square, that would explain it, as the wall was created during the turn - but it's unlikely that a modern game is coded this way so I doubt that's the answer.]
I'm guessing this a problem with the large weapon trait and 2x2 figures. Tvericus presumably had Large Weapon attached at the time?
Well, since I didn't take a screenshot, it's possible I made an error. But I'm pretty sure I planned it correctly, i.e. checked that the Large Weapon trait was still on him, cast Wall of Stone on squares including one beside him, and still had him hit someone in melee during the same turn.
Don't worry, you are not alone with that, it's one of the more arcane mechanics of Card Hunter. I was quite surprised by the bit smash on the head as well