The 25-year-old was given his marching orders by referee Willie Collum for a tackle on Aberdeen striker Stevie May, whic saw him win the ball before following through on striker May's ankle.
The dismissal was Jack's fourth red card of the 2017-18 season, but two of the three prior to Sunday's 2-1 win at Pittodrie had been rescinded.
Richmond, 45, who refereed in the Scottish Premiership for a decade between 2010 and 2012, claimed Jack's tackle was more than deserving of a red card but claimed Scotland international Jack got caught up in the heat of the moment.
"It's a red card every day of the week," Richmond said. "He's gone to play the ball and he's carried on and run into May knowing full well what he's going to do. He's looked to go in and win the ball and then go through the player.
"You can't start labelling a player as dirty. A couple of his red cards have been rescinded. He's just made a poor decision with regards to the type of challenge he's made on May.
"He's playing against his previous club. He's moved to Rangers, it's a difficult fixture. Sometimes you get caught up, but what makes good players and great players is when to pull out of the tackle."
The Daily Record claim Rangers are to appeal the three-game ban looming over Jack, which would see him miss Saturday's clash against Ross County as well as encounters against St. Johnstone and Hibernian.
Rangers earned their second win in five days against Aberdeen despite Jack's red card against his former side, thanks to goals from centre-back Danny Wilson and newly-converted striker Josh Windass.
The win sees the Gers climb to second in the top tier of Scottish football, leapfrogging Derek McInnes' side and they now remain seven points behind Old Firm rivals Celtic.