Again, the lightning is not connected to his fists or arms in any of these panels. Luffy clearly used CoC
He did not use CoC, go reread all the instances where Luffy used the 3 forms of haki.
Luffy clearly used CoA against Kizaru, stop pushing your agenda.
- CoA: it's a simple clash, with thin lightning
- CoC: it's a clash that always has an effect on the surroundings: we see stuff get destroyed/moved, the skies get split, people go unconscious (Luffy vs Katakuri CoC clash, Luffy vs Doflamingo CoC clash...)
- aCoC: it's a clash that has always been contactless and the lightning is thicker