Any details/sources on this? I thought it was strange that the airspace seemed almost entirely uncontested. Scrambling fighters take a while of course (particularly if unmaintained and you're corrupt), but I had at least expected some ground-based air defences to be active. Maybe they were being blown up in the first few videos that surfaced? Unless they were disabled by other means, that's another catastrophic display of the Russian systems.
In addition, USAF/USN have been flying ELINT platforms (e.g. RC-135s) off the coast for months now.
So even without the cooperation of any of the Venezuelan military, it's possible the mission was:
1. Precision long-range strikes on air defense radars around Caracas (and possibly assets)
2. Closer SEAD with F-35s to clear a path
3. SOAR Delta Force infiltration with tactical air suppression
4. CAP from F-35s to intercept any scrambled fighters
5. Exfiltration along same route
If the intelligence was good (location of air defenses and Maduro), it's entirely possible the above just went off cleanly.
See: Desert Storm air campaign. Having capable anti-air assets doesn't matter when your enemy has access to more timely intelligence and the means to do something with it.
I think that might be a step too far, rather I'd guess the US just knows the Russian systems very well. The success of the latest campaign against Iran shows that too, and if anything they learnt even more from that.
Either way, although Trump might every now and then be a bit too friendly with Putin, but a) cooperation at this scale and b) the bad looks and damage to Russian investments I think makes it seem unlikely. Putin doesn't stick his neck out for others unless it serves him. I'm not that well read on the Russian involvement in the area though...