Already on a booking, the American defender clashed with Staggies striker Jordy Hiwula just outside the Rangers penalty box 17 minutes into the cinch Premiership encounter at Ibrox. County felt that Sands had two hands on Hiwula and that it was clear foul deserving of a straight red card, never mind a second yellow, given he was the last man.
Robertson waved play on and Rangers took the lead eight minutes later through John Lundstram, while Sands was replaced at the break by Rangers manager Giovanni van Bronckhorst.
Mackay was measured in his post-match press conference, but was clearly unhappy at Robertson’s decision not to dismiss Sands.
“I thought the first 15 minutes we were doing fine,” said Mackay. “We had a couple of chances down the left side. They are a very good team, a Champions League team who gave us the credit of playing a very strong team. I wondered how they’d go and they went very strong and shows how they take us.
“Sands pulls down Jordy with two hands around his waist. He’d been booked but it’s inexplicable how it’s not a straight red, never mind a booking which would take him off. They took him off at half time which shows what they think. I can’t see how anyone who sees it on TV will think differently. The dynamics of the game changes if he goes off. I’m not saying what might happen but Aberdeen against Livingston was 0-0, Livingston lose a player and it’s 5-0 to Aberdeen. The dynamics change and it certainly changed on that, There weren’t bodies in between, it was very straightforward.
"There was no need for him to go down, he rolled him and he was away. We are disappointed with that. It makes it more sore that we’ve had two players [Jack Baldwin and Ross Callachan] cited and banned retrospectively by the Scottish FA during the week. Two of my best players aren’t here then something goes against you like that. You need correct decisions to go for you at Ibrox.
Asked if he managed to discuss the incident with Robertson, Mackay added: “At the end of the game I wonder if Don realises something isn’t quite right because he said if he got it wrong he’d call me tonight. The fourth official didn’t say he saw enough. It’s one of those things. VAR will hopefully clear this up but it doesn’t make it any better today.
"I talked about it concerning our sendings off. For those retrospective ones the process has to be better. There needs to be someone who sits and watches 90 minutes of six games not Sportscene. There was one with five minutes to go in the same game that we never saw that should have been sending off.
"Today was point blank and it’s not something that can be retrospectively done at that point. After 17 minutes we were doing fine, they go down to ten and things can change.”
Rangers manager Van Bronckhorst also had his say on the incident, responding: “We already had James on a booking and I think it was a close call that went our way. Sometimes the call from the referee is against you, sometimes it's to your advantage, but it's the decision of the ref at the moment. For us, it was a positive call because it meant James didn't get his second yellow.”