My opponent is wielding Sword of Justice “After YOU summon a minion, give it +1/+1 and this loses 1 Durability.”
I played Cornered Sentry “Taunt. Battlecry: Summon three 1/1 Raptors for your opponent.”
The raptors got buffed and used his durability.
You can argue either that my sentry does the summoning, or that I do the summoning, but you cannot argue that my opponent summons anything.
Same issue happens against hunter if he has Starving Buzzard in play.
You are summoning for your opponent.
The hearthstone wording is a bit ambiguous, however the game checks summons for a player and has always treated them as by the player.
Honestly, I can’t think of a way to word it that’s short enough to fit on a card otherwise.
Cornered Sentry “Taunt. Battlecry: Your opponent summons three 1/1 Raptors"
…
Would be less ambiguous and not lengthier at all, in fact it is one whole word shorter.
I am a rules as written > rules as intended player in every game I play and this sort of thing really bothers me.
Fixing the wording is EASY and Blizzard can’t be bothered.
It’s definitely confusion.
However, for future reference - regardless of what card or effect causes a minion to be summoned and who played that, for the purposes of cards reading “whenever/after you summon”, minions are always assumed to be summoned by the player that gets to control them. And this is consistent throughout the game with all cards that use that text.