Mystery stonechat

I will make this short, as I am heading out again in few hours.
This morning I went with Rony and Meidad to Nafha, my favourite rarity-hunting site this time of year. Practically the first bird we had when we parked the car at half-light was a sweet little Yellow-browed Warbler - always bliss. Photos are a bit less...

We birded the site for a couple of hours. There were tons of Chiffchaff, quite a few Siskin, Hawfinch, Syrian Serin, but not much of interest other than that (eBird checklist here). Somewhat disappointed we returned to the car. By the car a pair of stonechats were holding a temporary territory. The male was a Siberian, but the female - what was it? From one angle it looked European, from another it looked Siberian. With this in mind, I thought to myself - why can't it be Stejneger's? We started picking up ID features - rich rufous rump with dark shaft streaks to longest uppertail coverts, rather rich mantle, strong bill, short primary projection. These features were pro-Stejneger's, but I was still uneasy with the bird. For a potential first for Israel, we had to get more evidence. I got some positive feedback from European friends based on back-of-camera photos, then a few less encouraging responses. I understand why - the overall appearance is not quite there, possibly - ear coverts not dark enough so no pale throat, strong supercilium, perhaps not rich enough tones - BOC shots were misleading, views in the field became increasingly difficult as temperatures rose and the bird became more shy. These are the only useful photos I manages to take, at long distance, before the battery died:

Without a spare battery, Rony's camera pivoted. Here are some photos, part taken by Rony, part by me using Rony's camera - thank you Rony:

Close inspection of the moult here reveals that this 1cy bird moulted all it's GC and two tertials - unusual for Siberian Stonechat, thanks Yosef!

This is the male Siberian Stonechat it was associating with:

When first studying the bird in the field, and in the first few hours, I was quite hopeful it's a Stejnegers. Then, I started to become more sceptical. Now I am in a neutral position - this is an intriguing bird and it could be either taxa. I want to learn more about it.

Tomorrow I'm returning there to obtain DNA samples - hope it sticks around. Stay posted!