he didnt have a problem with his friend
This isn't your middle school playground. They are coworkers first of all, probably not friends. He was asked a question, he replied honestly : They tried having one caller only at Lock-in, with the whole team and the coach trusting the caller. it did not work out. So now you have the primary caller, that prolly makes strats for the team and prepares stuff for the early round then another person (sayf) to help him with the calling by doing midrounding instead.
If you have gotten anything else other than what i just wrote then you are the problem, not sayf. making up stories in your head and thinking this isn't a job and instead some teenage drama in some friend group. If you did get it right, then there is nothing in the situation that was wrong, everything was perfectly normal and happens in most teams, you just don't hear about it because they don't bother being as open about things.
Stop creating drama in your head, let the TL team do their thing and chill your ass down. i've seen you hate on Sayf repeatedly, it's cringe.