俺是低手，俺也来说一下

I think what she was trying to tell you is that when you make some minor grammar mistakes, you should let it go especially when you are delivering an important presentation or speaking to a large audience. To stop and go back to correct your mistakes will hamper the flow of speech and kind of remind others of the mistakes you’ve just made, which is even worse.

Minor mistakes usually won’t impact communication and most of times they don’t even catch much attention. People tend to have less tolerance of stammered speech than some minor mistakes.

If you are a perfectionist or easily get embarrassed with mistakes in public, do more homework before your public speech. In daily casual small talks, you can practice or correct whatever you want to get the hang of the grammar. Just don’t do that in formal speech unless it gets you misunderstood.

BTW, at least you should say Hi to me as an old classmate after long time no see. I’m zero tolerance of this kind of behavior, period. :)