[OscarCunningham]

It would definitely be ironic if a movie about honesty and integrity had been funded by a scam. This is sort of the opposite, the topic of the movie and its source of funding are thematically similar, rather than being in opposition. So rather than describing it as "ironic" I'd use an antonym like "fitting" or "congruous".

[zuminator]

The ironic part is that one might expect the producers of a film about a massive financial scam to be more educated and diligent about avoiding the same pitfalls in their own production. The fact that they were so easily gulled while essentially lecturing the world through their film, that's amusingly contrary to expectations, hence ironic.

[scruffyherder]

Gonzo movie making

[Top5a]

Ah, ninja'd!

[OscarCunningham]

The word "apposite" is much better than the ones I suggested.