I'm very interesting in simes' solving techniques but I am puzzled by the swordfish.., in the example quoted, he states:

"Look for three columns with only two candidates for a given digit.." and then

"At this point, we have a swordfish in the 1s. There are two candidate positions in column 6 - (2, 6) and (6, 6). "

I've studied and studied everywhich way but I don't get this... surely, in the highlighted columns, the cell (1,1) is a candiate for a 1, and in column 4, we have (2,4), (3,4) and (8,4) also as candidates for a 1 and column 6 has additional candidaes for a 1 in (3,6) and (8,6)

I'm missing something obvious but I can't see it! Help!