A live on line roulette has seldom any spot of the carpet free, it is of no use of cheating. They are sure to get theire hold anyhow. If a casino do not pay winners they will very soon get in problem, with the authorities, and the force of the market. Without winners a casino will not survive.
There are dishonest casinos, but a webbased casino can be checked up with the license authority, and the scam casinos have no license . Eu and Caribbean has not lose controls, and very few casinos provide the random numbers by them self, it is a service provider.
Some has a system for checking afterwards the number was chosen before the play, eliminating any cheating with those numbers.
Actually I know of some who thought about cheating, had a friend to visit the casino, noting down the numbers, and they where exactly the same as on line, he could even see his friend playing on the very same table.
"In the long run" casinos earn most playing fair.