Another Plot Hole?

Rewatching the film again and noticed something i don't think anyone else has commented on.

After the Team go through the ring Tails says Sonic look Shadow and Robotnik sacrificed themselves to save everyone.

Ummm but how does Tails know Shadow was there? Last he saw Shadow the Eclipse Cannon pushed him away when Sonic lost his Super state.

Robotnik makes sense as he was the only one left on the station when he was thrown out of it by Knuckles.

So why did Tails just assume Shadow was there as well?