This is why you should never ever lose your eye on the money you are betting. This is the reason why I always double check or even triple check the amount. I was a victim of this mistake myself that's why I learned my lessons the hard way. I remember betting .0005 and I lost all my money since I forgot adding another 0 after the point. Ended up betting .005 btc.
Honest mistakes that really ruined your day after realizing that all funds that you have are all emptied. You need to double check and keep your eyes with the amount that you select before starting the game, hard lesson to learned but that's life around gambling activities.Next time make sure to be attentive and not to make same mistakes again.
Although I agree that adding 0.0005 instead of 0.00005 was his mistake, being a Bitcoiner one has to be fluent with decimals but there is another aspect to his loss i.e. the tricky interface of gambling sites. They usually enable options like 'double bet after every bet' in default thus making it easy for users to lose everything fast. So I don't recommend people to use automatic bet unless one becomes too familiar with the site.
Mistakes like these are common because there are really some days 
