It couldnt have been only because of the huge withdrawal however there has been recent complaint in the past to satoshibet about the site not using automatic withdrawal anymore (references and complaint below) .
Ever since that there are few players that actually won a big amount from the no deposit bonus code, this step is taken to verify if any fraudulent way is used it seems. Another reason on why withdrawal is pending could be that the hot wallet is depleted at the moment
that is bad for the player lol withdraw not immediate
Not always the case, if you gamble up recklessly than this will be the case. As a matter of fact, some gamblers actually still floating in profit despite that they are playing it until now though