I am not sure that we should be as categorical about the presence or absence of a 'çollar' in this species. CNM species Nos 4344775, 4344653, 2769062 and 3437108 also show dark markings in the collar region. I do not think it fits C. lysizona.
For what it's worth, I'll just add that this wasn't particularly small, especially for a Philobota (in my experience). From memory I'd estimate its total length at about 17-18 mm, and id did tend to hold its wings relatively flat, rather than tented.