Well okay I did a bit of testing.
If you whiff a very laggy normal, like Mariah A3 or R.Soul A2, and the opponent throws you at any time during that normal, you still have the potential to throw-break (tech) out of the throw, even though your move was interrupted.
In other games if you are thrown out of a move you lose your throw break potential.
In Jojo’s this applies to normals, specials, stand, and supers though.
So for example, even if you perform Mariah’s qcb+AA super and it’s blocked, you can still tech a throw if the opponent tries to throw you during the recovery (post block).
I think the only time you’re not allowed to tech is during a roll.
But this means you can kara a tech attempt during another move. Such as c.A1~c.A3, provided you were holding down+back.
If you’re thrown during the A1 while you’re inputting the :db:+A3 then you’ll tech, and if you aren’t thrown then the A1 will come out.
Also, it seems that throws are instant or 1F. Looks instant to me looking at the frames. And the tech window appears to only be 2F as well. Simultaneous throw attempts result in a throw break, and you are given 1F after the opponent’s throw to break the throw (1F after catch frame).
That would probably explain why you guys are having so much trouble teching in netplay (I personally don’t have any trouble since I play with people very close to me). It’s not really a just-frame but a 2F window is still really really tiny.
More tidbits:
You can be thrown out of jump startup, at least by normal throws. R.Soul’s vertical jump startup appears to be 5F, and he can be thrown during any of those 5F, including the last frame where he only has 1 foot near the ground and appears to already be airborne. Oddly, if you attack 1F after inputting the jump you apparently get off the ground faster and can only be thrown during the first 2F, reducing the jump startup by 3F. This suggests that walking backwards or maybe backdashing is much better than trying to jump out of a throw. But of course you’re still very vulnerable to combos regardless.
The properties of being thrown on landing is even more bizarre. There appears to be a mysterious 5F gap where you can’t be thrown, but you can be thrown for 1F before the gap. To elaborate, while you’re landing, just before touching the ground there is exactly 1F where you can be thrown, then the next 5F you can’t be thrown, then any time after those 5 you can be thrown. And these frames seem to persist as such regardless if you attack with a normal attack or not. Even if it happens to be a ground normal, you can’t be thrown during those frames. Meaning you couldn’t be thrown of of a just-frame c.A1 on landing because c.A1 is fast enough to come out before the throw inv. ends. Unless you were caught during that exact 1F before you even land.
Very strange.
[Edit]: And on wakeup it seems there is a 2 or 3F window where you can’t be thrown (but you’re fully recovered).