This seems to extreme. Starting with 2%, likehood is he was diluted 50 - 55% across the 3 rounds. He end's up with 1.1%. Given the $390M exit, he get's $4.2M. This doesn't take into account liquidation preferences, but also doesn't take into account incentive plans either.

Let's say due to liquidation preferences he only takes half of that ($2.2M). Given that he just made $2.2M and Salesforce is keeping RelateIQ as a whole subsidiary, they'll want to make sure they retain the talent. So they will probably sweeten the deal with an incentive package of 60%-80% of that(1.3M). All in all, given he stays 3-4 more years, he'll likely come out with 3.5M to 6M.