If I am reading the Wikipedia article correctly (and if the article itself is correct), the benefactor does pay tax on that 5%.
However, if the OP had kept his startup in his own name, then at the time he sold it, he would have had to pay capital-gains tax on all of his profit, that year. (And then he would have been able to spend the remainder on whatever he wanted, that year.)
However, if the OP had kept his startup in his own name, then at the time he sold it, he would have had to pay capital-gains tax on all of his profit, that year. (And then he would have been able to spend the remainder on whatever he wanted, that year.)