I am a retired computer programmer with years of experience in writing code. I am also a former Microsoft and Novell network engineer. I'll take an informed SWAG (Scientific Wide Ass Guess) at the issue you brought up.
In order for the regulators to conduct their tests, the chip must be created with standardized architecture. I am sure the game manufacturers and the regulators are on the same page with this standard. The State employees who run these tests are not computer engineers. They are only trained to run the test and report the results. Any deviations from the standard chip set would be detectable. Rumors to the contrary are unsubstantiated. I did read of a situation where an engineer reprogrammed a specific machine with a jackpot "back door". That was many years ago and it was detected.
As I have contended, I don't believe the regulators test anything off the motherboard. This is why I believe some casinos are using poor machine maintenance to increase their return to be closer to slots. This is very common. You almost never find a slot machine with bad buttons, only video poker machines.
Some members of this forum have stated they believe the networking of machines facilitates cheating. While theoretically possible, this would also be detectable by the regulator's tests.
The truth is anything is possible. The real question is "Why would they cheat when they would be risking their license and risking the loss of customers if discovered? If this was discovered in some unregulated casino out in the boon docks, it might be plausible. Widespread cheating in Las Vegas? I seriously doubt it.
Casinos don't need to cheat. Very few positive video poker games exist anywhere on a regular basis. Those that do are in quarters. What casino is going to all the trouble and expense of creating and installing an outlaw processor to screw you out of a $1,000 royal flush? My home casino in Tampa reportedly nets close to a $Billion dollars a year in revenue. If they're cheating, they are doing one hell of a job.
I also believe the ability to play video poker 100% computer perfect forever is pure fantasy. Can a 72 year old like me do it? Can you? Captain America backup by both Batman and Superman can't either. If someone could and it started to hurt the casino financially, he would be banned faster than you can cash a white ticket.
The best way to treat this is to play where you feel the machines are fair. If no casino gives you that confidence, don't play video poker. The machines are fair. The RNG picks numbers out of the air totally at random. Anything can happen and it probably will. After it does, there will always be players who think it was engineered that way.