[Ulysses]

You asked if you could do anything differently, so I'll give you a couple of suggestions.

1: Make sure that your declaration is loud and clear.

2: You said your opponent only had 150 left. When you say all-in, push a couple of stacks out that clearly cover him.

These are the kinds of things you can do to help prevent this type of mistake from happening.

However, while it's annoying when you end up losing when you "would have won," this kind of mistake (just like accidentally exposing a card) happens all the time. Sometimes it works out in your favor, sometimes it works out in your opponent's favor.

Sometimes the dealer accidentally flips up a card when dealing that would have given you Aces. Sometimes one of your opponents was dealt 99 and the flop comes A92 and you would have busted him had the card not flipped up.

In each of these situations, though, you and your opponents got random cards, and the board had random cards. Whether or not those cards were the ones that were "supposed to be there" is irrelevant.

Sometimes the dealer shuffles the cards one more time than standard or gives them an extra scramble. You don't complain when you get crappy holecards after that happens, do you?