When a player receives report(s) from ONLY his opponents, IFS should ONLY focus at his ALL-Chat.
it seems pretty easy to implement this change on the IFS. so why not ? one less innocent player being punished.
pretty much, if your opponents report you for your chatlogs (and none of your teammates), you should be judged based only on your all-chat, and not your team-chat.
Just as someone who spams racial slurs and insults in a game, does not get checked/punished by the IFS if he does not get reported in that game(*), in the same way, someone who does not get reported by his teammates, should also not be checked/punished by the IFS based on his team-chat, in case he got reported by his opponents for whatever reason, and should instead be checked/punished only upon his all-chat.
(*) proof from Riot Tantram https://boards.na.leagueoflegends.com/en/c/player-behavior-moderation/MdZ4t8pl-hey-tantram-i-would-like-proof-ifs-considers-non-reports?comment=00010000