McDaniel said that "over 1,000" were invalid in Hinds. What he didn't mention was "so far" and "for all reasons", since there is no way that his campaign has, at this point, examined even a small proportion of the voting books. He is likely throwing out "over 1,000" to indicate that it it going to end up as a big number.
It had previously been 800, so they are working through them. I doubt its just 1000