You didn't. I quoted an incorrect source. My apologies.
Doing some more thorough digging through Broadcasting Yearbooks, it looks like
KEYT had NBC as its primary affiliation through 1962, with CBS and ABC listed as secondary. At the same time, KSBY was showing CBS as its primary and NBC as its secondary.
The 1963 yearbook shows KEYT as having ABC as its primary and NBC as its secondary, with no change at KSBY.
In the 1964 yearbook, KEYT was purely ABC. KSBY still showed CBS primary, NBC secondary.
The 1965 yearbook shows KCOY as on the air as of May of '64, but unaffiliated. KEYT still ABC, KSBY still CBS primary, NBC secondary.
The 1966 yearbook shows KEYT as ABC, with KCOY and KSBY both CBS/NBC (hopefully covering what the other missed).
Same in '67, '68, '69 and 1970.
1971 shows KSBY as being pure NBC, but KCOY is still listed as both CBS and NBC. KCOY finally shows as purely a CBS affiliate in the 1972 Broadcasting Yearbook.