If Dean chooses the capital raising via a dilution of shares, he will still own 70% of the total company value, including whats on the balance sheet and in the case of 2000bitcoin, he would own 1400btc in equity.
Regarding the above point, the 2k btc is a representation of the value of 30% of the company value, not the whole value. Dean also have mentioned that if the raised amount is 2000 btc, he has to sold the whole company at ~8000btc so that the 30% of investors will at least get back their original amount.
So in this case, assuming it successful raised 2.1k btc which will represent the 30% of the company, dean will automatically has the '70% stocks' worth of 4.9k. And this create also a bigger problem, the investors are not just investing to try to grab a bit in the profit like the old ways of betking. Now they also have to consider the estimate price of the whole betking and invest accordingly, otherwise if it is overvalue, it will turn out the 30% share will be traded lower than the ICO price and if dean want to raise more amount by selling his own share, it will 'add' more shares into the existing 30% market and further diluate the market.
This is the just the individual risk assessment that i made for myself.
I'm fairly sure that he'll have 70% in the end whether or not we go over the 2,000 BTC goal
EDIT: Also, bodgybrothers's point only stands if Dean goes the ICO route and these tokens are tradeable, thus allowing the market to set the value. Plus, this is assuming the general public understands that a 'stock' is only worth the present value of its future cash flows