This is a passive sentence, right?

I recently received a marked assessment from my teacher, and I think I might have been mismarked on a question.
The question asks : "Identify and analyse two examples of passive in the text". One of the examples I quoted was as follows: (transcript of radio)
"The Success isn't er fitted er with that type of capability."

I was marked wrong on this one, but I'm pretty sure it's passive, unless it could be interpreted as having "fitted" as an adjective referring to the state of being "fitted", in which case it would be active?

However, because of the predicate "with that capability", I have good reason to interpret "is [not] fitted" as the verb of the sentence, in which case it is passive.

Hence my post here to see if there would be any general consensus on its classification.

Thanks! :)