"Automatically Escape" Items

[Gidoza]

Some items say that you can "Automatically Escape" from any combat (EXAMPLES: Instant Wall and The Other Ring), whereas others, like the Potion of Invisibility, indicate that one must use it after the Run Away roll fails.

Am I to infer from this that "Automatically Escape" items/abilities are to be used BEFORE/IN LIEU OF rolling the die? Or can an automatic escape be initiated even after failing a Run Away roll?

Thanks.