They obviously did sign up for the transaction to 'fail'. In this case, it just means others paid more for their place in the line than they did. They absolut

They obviously did sign up for the transaction to 'fail'. In this case, it just means others paid more for their place in the line than they did. They absolutely picked the price they were willing to pay and lose, in the hopes it was more than the others trying to get a place in line. So yes, they absolutely knew their transaction could fail if others paid more than them.