Can I Give a Sneak-Attacked Ally to Another Player?

By conykchameleon, in Rules questions & answers

Sneak Attack: Put 1 ally card into play from your hand. At the end of the phase, if that ally is still in play, return it to your hand.

Can I Sneak Attack Gandalf (or someone else if you're doing it wrong haha) into play under another player's control? There doesn't seem to be anything preventing it, but I just wanted to make sure there wasn't something I was missing.

I believe no

From the rules on core set

Control and Ownership
A player “owns” his heroes and the cards that he has
chosen for the player deck he is playing. A player
“controls” all cards that he owns, unless another player
or the encounter deck takes control of the card through
a game effect. Any time a card leaves play, it reverts to
its owner’s hand, deck, or discard pile (as directed by
the effect forcing the card out of play).
When a player plays an ally card, it comes into play
under his control and is placed in his play area. If
another player takes control of that ally, it is moved to
the controlling player's play area. Ally cards cannot be
played under the control of another player, they can
only change control through card effects.
When a player plays an attachment card, he has the
option of giving control of that card to another player
by attaching the card to one of that player’s characters.
Players always assume control of attachments that
have been played on their characters. If control of
that character changes, so does the control of any
attachments on that character.

I understand what you're saying, but those rules are only governing when you "play" a card. It has already been established that "play" is different than "put into play", and I can find no such restriction on "put into play".