Diane Dodds (DUP) + 24,462 = 115,722
Alban Maginness (SDLP) + 2,614 = 97,428
Nicholson is over the quota (which was 121,144), so he is elected.
Votes left in the system: the SF surplus of 5,040, and Nicholson's surplus of 11,113. Even in the unlikely event that they all went to Maginness, he would still be more than 3,000 votes short of Dodds, so she is elected.
(pwilkinson - I failed to report the 7,548 untransferred votes from Alliance and Greens, which possibly threw out your calculations.)
So 53% of Allister's votes went to Nicholson, and only 35% to his former party.
On this basis I fancy his chances of winning a seat at the next Westminster election are good, esp in North Antrim which has a history oif maverick election results going back more than a century.