In an anime I heard this sentence:
どうして私と戦おうとしないの？私が怖いの？
which is translated as "Why don't you want to fight me? Are you scared of me?". I'm not sure why が is used here: I found that 私は怖い means "I'm scared", and I'd have expected 私が怖い to have the same meaning, with 私 marked as subject instead that as theme; I tried to read again the question about those particles, but I'm not really sure if it applies in this case, since it doen't seem to fit in any of the usages listed.
What role has が in this case? If the sentence can mean both "I'm scared" and "[someone is] scared of me", it's context the only way to discriminate?
