In the middle of Homefront, we hear that the Changelings know that
Odo killed one of them
(in the earlier episode The Adversary).
How it this possible? How could this information reach The Great Link?
From our perspective (the viewers, Odo's, or the Federation's) it went like this:
- the Changelings send one of their spies to spy on the Defiant,
- Odo kills him,
- therefore the Changeling spy does not return to the Great Link.
But from the Changelings / The Great Link’s perspective, the "Odo kills him" part is missing.
So, they may think (at nearly any particular point in time) that:
- the spy hasn't yet finished his task or was forced to hide,
- the spy is captured and kept in some Federation detention center, or
- the spy is killed.
The fact that he hasn't returned to The Great Link does not imply that he was killed. And even if they assume that he was killed, that does not imply that Odo killed him: the Federation has many ways to kill a Changeling once captured, and Odo hasn't got any special abilities that make him the only one able to kill another Changeling.
Thus, to my knowledge, it wasn't possible for The Great Link to learn that one of their spies was killed by Odo and this is a screenplay gap in Homefront. Can anyone confirm that or tell me what am I missing?
The assumption that Odo and other Federation members learn that The Great Link knows that Odo killed one of them is even less possible to prove, assuming that Odo had never visited The Great Link in the period between killing the Changeling spy and the events shown in Homefront.