We have three cameras outputing 1080i/50 to Aximmetry, following usual keying procedure (Advanced B w/cleanplates, adjusting mainly High & Low Cut), yet every single one of the compositgion resulting thin white outline for bright things such as skins and bright clothings.
To me this looks like artifacts from the keying process.
In the second image, the area between his fingers is probably green, but the built-in despill makes them look white.
Is there a reason you're using interlaced footage?
Interlaced basically gives you only 1/2 the vertical resolution to pull a good key from....
I would suggest going 1080/p50 (or even p25) and look at the Matte output of the keying module while adjusting your settings.
Cheers & all the best.