Being toxic for any reason is never okay. There's healthy ways to communicate, and if they don't want to partake in that it's their decision, Mute them, Report them, and go on to the next game.
Constructive criticism and healthy banter is always encouraged, helping your teammates improve is a great thing that will separate you from the rest of the flamers. Try not to use terms like "basic X knowledge" as it's somewhat demeaning to hear as they're playing the role the way that they see fit. I can definitely see how this "triggered' the individual, however it's no excuse for being toxic to someone having a bad game. Saying things along the lines of "gg noob jg no ganks ff20 9x report plz" is always going to have a negative connotation associated with it, and will almost certainly have a demoralizing effect on the team.
Saying something more productive like "Hey (insert jungler name), Riven picked up Ignite instead of Teleport, if you're around can you help me out with her? We can put her super far behind and I can help you get into their jungle or roam around/grab towers." If they decide to flame you, so be it, just Mute them and use Smart Pings to communicate at that point. More likely than not, your teammate will attempt to communicate with you though - if they tell you something you don't want to hear you need to be prepared for that as well, such as "Sorry I can't go top right now, I need to clear my Red side and help bot lane out I think Lee is getting ready to dive them."
Even if they guessed wrong and Lee was busy getting juked by the Scuttlecrab (queue Silver Scrapes and mastery emotes pls), it's okay. Try not to flame them and do your best with the cards you've been dealt. You can always try to encourage them, however don't press the issue as it will likely turn into an argument rather quickly. Something like "Np I'll try and play safe for a bit. Let me know when you're nearby though so I'll be ready!" That encourages them that you're willing to communicate and that you still need assistance or are willing to work around their schedule to a degree. Sometimes you'll even get a friendly mid laner that will be able to push our their wave and run up to help you when they see that you're a friendly individual that's focused on team play. A small "ty" goes a long way if they make the effort, even if nothing comes out of it. They've gained you a lot of pressure and sacrificed their own by showing on the map.
TL;DR: It's never okay to be toxic for any reason. Try to avoid being passive aggressive as well as humans tend to pick up on that stuff quickly, even if the IFS (Instant Feedback System) doesn't and it will affect their playing ability. Everyone has bad games, even God Faker himself messes up every now and again and goes 0/10 on Azir (SHURIMA!). It's part of the learning process and if someone is flaming an individual for poor performance it's likely not going to help them improve - usually it has the opposite effect!
