The Gers boss made the claim after seeing top-scorer Alfredo Morelos return to his bad old habits as he was dismissed moments after grabbing the visitors' second goal.
The Colombian - sent off five times last year - received his usual abuse from the terraces but got his own back when he followed up Nikola Katic's first-half opener to put Rangers 2-0 up.
But the smile was wiped off his face after he was shown a second yellow card for aiming an inflammatory gesture at the Well fans based in the East Enclosure during his celebrations.
The home side could yet find themselves in trouble after the Well support responded by raining a number of objects down on the Rangers players as they tried to shy Morelos away.
Gerrard had no complaints with the decision to dismiss his striker - who will now sit out next Friday's crucial trip to Easter Road - but reckoned it was only a matter of time before Robertson reached for his top pocket.
The Rangers manager said: "It's the first setback Alfredo's had after huge, huge improvements so we'll reset that but we certainly have no complaints.
"Unfortunately, the supporters and his team-mates will suffer because he's not available for the next game.
"There had been a bit of a commotion at half-time between both sets of players, although there wasn't much in it.
"However, when I saw the referee book Ryan Jack and Declan Gallagher before the start of the second half (for their part in it), I thought that he was waiting for a moment.
No complaints over red card
"As I said, we have no complaints about the red card but I felt he was desperate to give out a red card today. I had that feeling from the side, which is unfortunate because our player does get that type of abuse.
"Alfredo was unplayable. It is a setback today, he knows that, we know that. I'm sure he hates getting punished in the pocket so hopefully he will get back on the horse and continue to improve in that area."
Defoe to lead line against Hibs
Jermain Defoe will now have to lead the line against Hibs, and Gerrard revealed he had been trying to get the Englishman on when Morelos was sent off.
"We tried to take him off, for a couple of reasons - because he was already on a yellow but also because we were flashing balls across the six-yard box and I felt that someone with a bit of nous and experience would have had a tap-in today," said Gerrard, whose team returned to winning ways after drawing against Aberdeen and Young Boys either side of their Betfred Cup final defeat against Celtic.
"Jermain might have been that person but I couldn't get him on before the red card came out.
"But the result is exactly what I was looking for - a strong, solid away win. We were fantastic defensively and had a good base and structure about us."