During the early safety car period that was triggered when Nicholas Latifi crashed, Sainz had emerged from the pits very close on the track to Red Bull rival Sergio Perez.
But, despite being ahead at the safety car line that defines who has position in the queue, Sainz lost third place on the road as Perez accelerated out of Turn 2 and forced him wide.
Ferrari spoke to race control about the situation, as Sainz being ahead at the safety car line meant that Perez should have to give the position back.
But despite clear television footage showing that Sainz was indeed ahead, the FIA delayed making a call on the matter and it was not resolved until after the restart.
That meant Sainz never had an opportunity to challenge Max Verstappen, who would have been ahead of him, and then both he and Perez lost ground as they switched places.
Sainz was not happy with the situation as he felt it was very bad for racing.
"In the end, we created a mess that for me is unnecessary, given the fact that we did six laps behind the safety car and there were millions of opportunities for Checo to let me by and have a good fight at the restart," explained Sainz.
"If I would have got passed by George Russell for example, what would we have done? Would Checo have had to let by Russell and me, which would have been tremendously unfair for him too, or then Checo doesn't give me back the position because there's Russell in between me and him and it's tremendously unfair for me.
"It's just these kind of things that, as a sport, we need to keep getting better at because I think we need to simplify things and just make it more quicker and easier for everyone to understand, and even for the drivers to go racing with a much clearer mind."
Ferrari team boss Mattia Binotto agreed that the FIA was too slow in making the call, and that consequently that made it unfair on Sainz.
"I think it took a bit too long from them to decide and to give that to the stewards," he said.
"Finally, it seems that they took the decision when the safety car was coming in and it was too late to swap before the restart. So it's not a blame, but it seems that in those types of decisions, we need to speed up because it was obvious and straightforward.
"I think it could have been done differently and I think it would have been important to do it differently.
"It would have been a lot more fair and equitable to swap the position before the restart, because that was the right position to have and for the battle of the restart as well."
Sainz reckoned that the matter was something that needs to be addressed with the FIA to ensure no repeat problems in the future.
"This is our number one priority now that we need to talk with the FIA, because basically Checo lost the opportunity to fight with me at the restart, and I lost the opportunity to fight with Max for not giving up the position during the safety car," he added.
"We had a lot of laps to do it. The FIA did not allow us, and I think for the sake of racing and the sake of F1, these kind of things they need to happen quicker and they need to happen more efficiently."
