Questions are hard to have toxicity AND work as real questions that have a goal.
If you'd like to be technical, then slander (which is basically a "he-said, she said OR he-did, she-did" situation) which is in fact AGAINST the T&S of your league account, and the comment of "Don't be daft, kid" with the specific word "kid" could indeed be taken as toxic and reported.
There'd be no point to a report of that scale, true.
Don't get technical if you aren't gonna at least research the technicalities.
It doesn't look the best for your reputation, or to people who aren't of the same thought process.
Not to mention that there's nearly no point to having an automated system which can't detect sarcasm... be able to ban someone instantly if they use key words like "feeding, deserve, win, game" within a set of 5 sentences.
That'd be the way to do it, unless you want riot to slow down production of EVERYTHING to a crawl... just to check for people using those words.
I can imagine the automated banned people showing thier chat logs as:
XXBOBtoplaner: "Sorry guys that I was feeding, I don't deserve to win this game with the awesome people like you"
SupportiveHIGHFIVE: " your good bro, you just had a bad game. You deserve to win as much as us bro"
AliveShooterBro: " no worries, you kinda sucked but you brought it back a lot. Good job on that"
By the automated system you would just about need installed,
XXBOBtoplaner and SupportiveHIGHFIVE would be banned.
They weren't inting, trolling, or being sarcastic...
You have to think of practicality in how something is implemented
Riot's current system can't catch everything on it's own
That's why there is a report button at the end of a game and chat logs for in-game
It is so that YOU, the player, the 3rd most important part of what's making the game big...
Can help make league better with every second you spend in it.
(first two things of what is making the game big is the game itself and the company support, everything I say is liable for argument as it's almost entirely my opinion plus speculation from my experience and research as a future game dev).