Ah, I see... yeah, that trick isn't that easy and often underestimated!
I find it very helpful to turn your wrist so wide that you can see the string, that helps catching the diab.
And make sure that the string is as wide as possible under your shoulder, as Matt_ said:The bigger the triangle, the better.
If you've the diabolo_comp vid, you can see a special walk movement Matt hall does. Try it! maybe it helps
If you don't grab your sticks at the very end while playing, prepare when you're going to do the trick and move your hand yet when you begin the overarm satellites to the end of the stick. (e.g. while doing a sun)
I find it a bit easier, especially when doing this trick with the string behind the back (eric trick), not to throw the diabolo straight to the right, but even a bit to the front and not as far to the right as normal.
The rest is practise... And sometimes the diabolo hits the stick... But that's not that bad, it happens, to me, too (sometimes). Mostly, it doesn't even influence the stability 8right word?) of the diabolo, only the spinning speed(right word?)...
By the way, I got a camera for christmas, when interested, send me a personal messageand i could make a short tutorial, but i don't think it's necessary...