Celtic were involved in three controversial incidents over the weekend in their 2-0 defeat away to Heart of Midlothian in the Scottish Premiership. First of all, Hyunjun Yang was awarded a penalty early on after being caught in a tangle with Alex Cochrane, leading to Adam Idah spurning an opportunity to put the visitors ahead. Of course, this directly led to the South Korean winger’s dismissal, as he was sent off following a high boot on the same player. Don Robertson initially booked Yang for his challenge before being summoned to the monitor and changing his decision to a straight red card. …