Sure, lab safety goggles will protect you from pepper spray in most instances. But what eye protection you're wearing won't matter. You're chained to a tree. The cops can do literally anything they want to you, including ripping your safety glasses off and emptying a can of pepper spray directly in your eyes. See: the infamous case of the Pepper Spray 8
Deputies pepper sprayed Mike McCurdy (above) and Noel Tendick directly in the eyes at close range while they were locked together through the tracks of a Pacific Lumber bulldozer on an old-growth redwood logging site. The activists endured the torture and did not unlock. Deputies then safely cut them loose with a portable grinder, as they could have done without using pepper spray, and as they had done hundreds of times in previous years.
The ruling is also meaningless. They ruled the US has to "facilitate" his return, but does not have to "effectuate" his return. The admin will interpret this to mean that as long as El Salvador doesn't take active steps to send him back, the US doesn't have to do anything to try to make them.