I'm pretty sure savory and savoury are synonyms. In fact I'd say they are the exact same word in slightly different spellings - like flavor and flavour. Both MW and the OED list them as variants of each other.
I guess I can kind of see how the clue works with "savory" as the answer. But I've never seen a "sounds like" clue used in this way. The answer sounds like a word that is a spelling variant of the answer... To me this is weird.
Take this made up clue:
Hue, on the phone. (5)
The answer is "color" because hue can mean color and color sounds like colour. Weird.