Learned this trick a while ago to tell the difference: don’t interrupt a person who you might think is being critical. just let them run on for a while and tap out for a bit.

If that other person comes off like they are harassing and verbally abusing when no one is being defensive to them it becomes pretty clear they are the toxic bully.

If they sound concerned and you not replying to it makes you look and sound dismissive, you’re the problem.

That said:

insulted too easily

Tends to be what an insecure toxic person says when people stop replying to their lashings.