Busquets handball, which pretty clearly lacked intent
I don't remember intent being required for handball. That said, I haven't seen the play in question, but Busquets is one of the worst embellisher/divers I've ever seen, so I'll just go ahead and say he's guilty.
Handling the ballHandling the ball involves a deliberate act of a player making contact with
the ball with his hand or arm. The referee must take the following into
consideration:
• the movement of the hand towards the ball (not the ball towards the hand)
• the distance between the opponent and the ball (unexpected ball)
• the position of the hand does not necessarily mean that there is an
infringement
• touching the ball with an object held in the hand (clothing, shinguard, etc.)
counts as an infringement
• hitting the ball with a thrown object (boot, shinguard, etc.) counts as an
infringement
Disciplinary sanctions
There are circumstances when a caution for unsporting behaviour is required
when a player deliberately handles the ball, e.g. when a player:
• deliberately and blatantly handles the ball to prevent an opponent gaining
possession
• attempts to score a goal by deliberately handling the ball
A player is sent off, however, if he prevents a goal or an obvious goalscoring
opportunity by deliberately handling the ball. This punishment arises not from
the act of the player deliberately handling the ball but from the unacceptable
and unfair intervention that prevented a goal being scored