The ball hit Antonio Rudiger on the arm as an assist for Trevor Chalobah, but this season’s handball rules mean Chelsea’s goal against Juventus was not disallowed.
Last season, the rules stated that any touch of the arm from an attacking player in the build-up to a goal was automatically cause to disallow it, whether it was considered to be intentional or not.
That was changed by IFAB this summer, so that is now only true if the player who scores does so with an arm.
Otherwise, intentionality is to be ascertained in the usual way.
In this case, Adrien Rabiot flicked the ball onto Rudiger’s arm from point-blank range.
The former Roma defender also had his arm across his chest, so arguably if the ball had not struck him on the hand, it would’ve hit his torso anyway.