A deduction by more than 60% is a robbery not taxation, imo. If lottery tickets are subject to sales tax then the winnings should be tax free
And I used to think the 25% my country imposes on lottery winnings was unfair!.
Still, ~$400 million is a huge amount of money so congratulation to the winner, whoever he is.
I thought that it'll be as much as 50%. In this case, it's more like your taxing the government when you're winning the lottery 
Anyway, I'll take whatever I can get when I won the lottery whether if the government takes 70% from it.
I don't mind if the tax will be much 30%-50% because I still have the most money from the lottery. I think it is okay with that, as long as we can take the rest money to our bank account and don't need to pay another tax, we still win. At least, we can beat many people who bought the lottery ticket to be the winner, so we still won much money with the cheap price of the ticket.
I only hope the government and the casino will not cut the win money too much more than 50% because we can get more money.