Zangief’s Ultra Combo is not like Akuma’s or Abel’s in the sense that the latter two, while appearing to be grab moves, require contact to be made with the opponent in order to inflict damage.
To get out of this situation on reaction, one can just tap (not hold) up during the Ultra Combo animation to avoid the move, as both require the character to be on the ground in order to connect (being in the jump animation counts as not being on the ground).
Zangief’s Ultra Combo, however is a true command throw which is instant, so if you are in range, you’re done on execution.
The frame data supports this (emphasis mine):
|Name ||Startup ||Active ||Recovery ||Block F.A. ||Hit F.A. ||Blockstun ||Hitstun ||Damage ||Stun ||Super Meter Gain ||Block ||Cancel Ability |
|Ultra Combo ||1+0 ||2 ||46 ||- ||- ||- ||- ||600 ||0 ||0/0 ||1.4 ||- |
That bolded “0” indicates that after the “intro” to the Ultra Combo, there isn’t any window of opportunity to react.
But along comes this video of the Korean National Champion in SF4 (he is playing Zangief):
At ~3:16, you see Zangeif enter into the animation for his Ultra Combo, which Ryu counters after the animation with a SRK.
The consensus over at SRK seems to be that the input for the SRK was put in before the Ultra Combo animation, and because at least the first frame of the SRK is invulnerable (to throws as well) it was able to counter Zangief’s Ultra Combo.
This makes sense, because I would never try to psychic DP if my expectation was that an Ultra Combo was coming out. However, on knockdown, with a player trying to cross me up, a SRK reversal is natural.
So it goes to show that Zangief’s Ultra Combo can be reversed, but only if you are psychic, and not on reaction.
Fortunately, there is this comment about Sagat’s Tiger Uppercut (all versions) in the frame data (emphasis mine):
1-5f invincible, 6-7f throw invincible, 8f~ airborne, opponent is in jugglable state on counterhit
Which means that in a similar situation (knocked down by Zangief who is trying to jump in/cross-up on wakeup), the Tiger Uppercut will get me out of a situation where Zangief might jump in early and try to Ultra Sagat on wakeup.