There's also some speculation that the Greek phrase he used was somewhat ritualistic and was potentially a curse, I believe acoup.blog or the associated Twitter account shared the research on that
It depends on which author you follow, the wikipedia page mentions (besides reports he said nothing) also reports he said something aimed to other people (not Brutus):
jaclaz|2 years ago
https://en.wikipedia.org/wiki/Last_words_of_Julius_Caesar