When Tom Wilson is going he is like a freight train. Wilson was hunting down the puck and took the most direct route to get to it and with Campbell leaning out to try and poke it away, Wilson caught the upper body of Campbell sending them both flying.
Wilson received a two-minute penalty on the play. Luckily for the Toronto Maple Leafs, Campbell remained in the game and was not called out by the concussion spotters, or worse, leaving injured.