They're right.
After you've posted, at the bottom of the box is an Edit button, which is there for five minutes or so.
If you use Post Reply, rather than Post Quick Reply, it allows you to preview what you're going to post, which can be useful in helping to spot mistakes.
I think the Edit button has a mind of it's own, and is a little timid
As soon as you see a glaring mistake you've made, it vanishes back ino it's little hidey-hole.
