Can you justify burning into your destination reserves(ie the 30 mins reserved for alternate holding), and NOT advising ATC that you have 'no holding fuel'.
I think if he was below his reserve fuel(alt+30 mins), he is completely within his right to say he has no holding fuel. And not declaring a Mayday either.
Only qualifier would be that now,s since ATC would not give him priority, it would become the ATC headache to make sure he has a more or less confirmed landing at his destination. Whatever that might be.