You can be sure exactly how easy it is because in a perfectly competitive economy everyone has perfect information, and the experiment's key assumption is getting away with fraud is a endogenous variable in the utility function. The fraudster can manipulate this variable to optimize their utility. This means that every actor knows exactly what they must do to avoid getting caught. It's a simplification so we can consider the implications of the notion that getting away with fraud is as easy as setting your mind to it. Another assumption is entities act solely in their own financial best interest. In this setup, everyone who will be better off by committing some form of fraud, which will be everyone who participates in the economy, will commit fraud.

Oh, okay ... but everyone having perfect information AND fraud being possible to get away with are fundamentally contradictory assumptions; fraud is based on exploiting some people not having perfect information.

They are not fundamentally contradictory, everyone would know they are victims, still if it is in their net benefit to participate, they will. Again, this is an experiment with unrealistic assumptions (getting caught is an endogenous variable), it is intended to bring to bear the the absurdity of the statement that one can control their own fate if they commit fraud.

This experiment just sounds like "what if fraud were not fraud"

From op:

>...avoiding the ire of the SEC is relatively easy if you set your mind to committing fraud without getting caught.

The experiment is a simple application of the economic theoretic framework to the statement above. Nothing more. There isn't all that much to argue about here, as long as you accept the framework upon which almost all of theoretical economics is based.