Hi,
One of the moderators was 'looking' at a members post and accidentally pressed modify, deleting part of the post.
Is there a way to get this back, or see what it said beforehand so we can revert to how it was?

Using 2.0.18

No, not that I know of. Pressing modify would edit any database info on that post. So, what was there is gone.

Unless you have a backup...

Hadn't thought about a backup. Would that not remove any posts made since the modification?

Yes, it would. So, it depends on how important the post was as to what to do. Either leave as is and have the moderator apologize for the mistake or do a backup.

On a side note, you can install the drafts mods so it can automatically save drafts of posts every so often to help.

https://custom.simplemachines.org/index.php?mod=1264

You could, I guess go into the backup and find and extract that post only and put it in the current database. If you feel lucky....

EDIT: Not sure how hard that would be. Probably not that hard.

I would restore to a test db & copy/paste the one post using phpmyadmin.

If the db backup is a .sql file, you can possibly copy/paste straight from there. 

Thanks guys, I've passed your suggestions to the site administrator. In their hands now