This is a very interesting discussion, WTM.
I do not have access to my bird guide but doubt that the ole Sassol would be of any use in this the case.

I did however go and look at the photos on BirdPics and picked up something that I want to mention….do not know if I’m again just confusing myself more with this.
On most of the photos of the Grey Tit-Flycatcher, almost the whole of the under-tail appears to be white, not just the outer parts…..where on the Ashy Flycatcher it is dark ….on Francois’ photo of a AFC, most of the under tail is still dark even tho there are some white present. I think where confusion might come in, is when you have a Grey Tit-Flycatcher that do not have so much white and it then might be confused with a AFC…..on BirdPics there is one photo of an GFC that do not have so much white under the tail.
So, would it be correct then to say that if the whole of the under tail is white, that is a Grey Tit-Flycatcher?
If you look at the other photo I posted on the forum of the bird I saw, you can see that the whole under-tail appears to be white….not just the outer edges.
Larger view
As for the white eye ring, I have to be honest, I think lighting etc can really cause confusion (for me

)….if I look at the last photo of the Grey Tit-Flycatcher on BirdPics (by Clive Kaplan), this bird also appears to have a white ring….but I’m not such an experienced birder and I’m sure the experts among you will not be confused by this as I am.
Another difference I can see between the Ashy and a Grey is that they Grey have obvious white (light) edges to the median wing coverts (I do not know if my terminology is right

)….what do the experts think?
JoelR wrote:
Concerning the difference between Ashy & Grey Tit-Flycatcher, I just want to add that the distinction is probably easier to make in the field than from a photo. When I saw my first Grey Tit-Flycatcher it was evident. The bird was behaving much more like a tit than a flycatcher: it was hopping around in a tree and sitting horizontally, rather than being perched up straight ready to swoop down on some unsuspecting 'fly'.
JoelR, I think I know exactly what you mean and in this respect the bird I have seen most definitely act like a the Grey Tit-Flycatcher…. I saw this bird again, 10 days ago (well, I presume that it is the same bird)…..only got 3 photos of it….not of much use…..and on this photo you can almost not even see the white under the tail. But this bird is VERY busy…. It does not sit still, not even for a second. On all 3 occasions I have been able to photograph the bird, it did not once sat perched up straight.
Just for interest sake….this one was actually following a Orange-breasted Bush-Shrike around.
Larger viewwildtuinman wrote:
My honest opinion is that there is some degree of hybridization between Flycatcher species. I will really make an effort to get my hands on some possible documentation describing this.
Eish…just to even more add to the confusion.

It will be really great to find out more about this, WTM