I went back and listened to the Nunes press conference announcement of March 22. The link is at https://www.youtube.com/watch?v=oxZNa4eYG0c.
After listening to the entire video, I'd like to comment about how the term he uses ("incidental surveillance") differs from the term you use in your question ("under surveillance").
I infer that whatever surveillance was happening was done legally, mostly because the interview mentioned that the material under discussion had been provided to Rep. Nunes because of his position, and was viewed by him as part of his job. He repeatedly used the term "Incidental surveillance". To me, this is saying someone was out watching for one thing when something else happens. And ... it made its way into the report for some reason.
To me "under surveillance" would mean that someone had been targeted for surveillance, and that the report was about whoever or whatever that had been targeted. Here, that is not the case.
Will Comey be fired? It seems unlikely that there is a basis for that. The video of the Nunes conference did not disclose who ordered the surveillance or why.
My guess is that Nunes may not know the who or why either, all he talked about was that it uncovered something incidentally that made its way into a report he read. He did not talk about who was targeting who for surveillance, nor did he talk about why.
I listened to the whole thing, and at the end I decided all he had done was offer up some fodder for the folks who like to jump to conclusions on the basis of rumor and innuendo.
As this plays out, perhaps we will all learn who the lemmings are.