This is a big reason why batch-based code review systems are great. I can quickly work through a pull request and point out every little thing that I notice because it's all a draft. Then I go back through and review my review. Sometimes things that I thought were problems are just things I didn't understand yet. Sometimes things I pointed out initially aren't even worth bringing up. And for the remaining points I can check that my feedback has the right tone and will come across well.
I really miss this cycle when I need to use something like google docs as a feedback mechanism, where all the comments I leave are immediately mailed out.
Slack is another system that encourages hasty responses. My critical feedback is better when I'm writing up an email and not participating in a realtime conversation.