Nasser admitted to using esceline, not synthol. Synthol and/or esceline use is as common among top pros as using toilet paper. In other words, the likelihood of a top pro never having used oil is as likely as one never having wiped their ass.
Now about the 2001-2002 pictures, the lumps in the delts are from scar tissue caused by plain old steroid needles like every pro takes. Nasser accumulated much scar tissue in his delts since he made the mistake of letting his wife repeatedly inject the same area, similar to Milos making the mistake of letting scar tissue accumulate in his arms at one point (which also gets mistaken for synthol). Eventually he surgically removed the scar tissue from his rear delts since they did not disapate on their own. You would never need to surgically remove synthol!
Everyone knows that Synthol works by creating spaces in the muscle tissue which scar tissue forms in to fill the void, thus making the gains permanent. The oil doesn't stick around forever, it is reabsorbed into the bloodstream and expelled.
Nasser having scar tissue removed does NOT rule out the use of Synthol, but instead it pretty much points to the fact that he did use it (which he's already admitted to anyway so there is no debateing this bigbobs).