Wow that's rough.
I don't really play Mystery Bounties but don't they usually have a list of the available mystery bounty prizes? When I watch people play them on twitch they always look back at the lobby or wherever to see if the biggest bounties are still available.
As unfortunate as it is if they knew it was a possibility you can't be too upset about it, it was going to end up happening to someone. If there wasn't a list of available mystery bounties anywhere and I got a $000,000 bounty I would be pretty upset, you risked a portion of your stack for a chance to win a bounty that then the tournament director decided to be a show boat and do a 1 of that isn't done anywhere else in the poker industry.
As with most things I think context can be a determining factor on if this was a rough troll or just a spot of bad luck for the guy who pulled the Nil ticket
GL
EDS