That would be hard. Reuters have not reported that RSA took $10 million, they have reported that documents leaked by Snowdon claim that RSA took $10 million.
They could sue Snowden. But I imagine, it will not payback as a strategy.
Maybe they should sue the NSA for writing misleading classified slides and then letting them get leaked. :-)
They would have to prove his info was false, and I doubt they can do that, given that Snowden can release secret info but RSA can't.