It's not possible for the page to not load properly and then automatically stand. Either:
a. The page did not load properly after betting/hitting/splitting and you can resume your game by going back to Blackjack (unless the result was bust I think)
b. You hit 'stand' and the page did not load properly meaning you can go back to BJ to see the result.
The game can't automatically load an option (ie. stand) without you clicking something, because each button has a different value and you have to select a choice.
Given that you claim the page 'didn't load properly' then automaticlly 'stood' and you know the outcome (you lost), I think the most likely occurence here is the new option:
c. You bet 3.5mil, stood and lost and now you're making up an impossible situation in order to try and fool staff in order to get your cash back.
Ofc this wont work because staff know that such a situation that you describe cannot happen.If your game did "stand" it's because you clicked it.