You should not do a calculation of probability for an event deemed surprising post hoc as if it were an event specified before it was rolled (observed).
It's very difficult to to do a proper calculation of post hoc probability, because what other events would have been deemed at least as surprising depends on what the context is.
Would three ones twice in a row at an earlier or later stage of the game have been as surprising? Would you rolling three ones have been as surprising as him rolling them? Would three sixes be as surprising as three ones? and so on... What is the totality of all the events would have been surprising enough to generate a post like this one?
(Even if it were legitimate to do the calculation as if it were a pre-specified event, it looks like you have that calculation incorrect.)