We had a user today delete the homepage of their site accidentally.  Due to this the site would not load, it just sat in an endless loop it appeared.  Is there anyway to prevent this from happening if an admin does delete a page so that it doesn't redirect on itself?

The only way we could fix it was to hit a subpage, then login and restore the home page from the recycling bin.

There must be some way around this for when this happens?  Any ideas/suggestions?

Is there a home page specified in the site settings?

If what you are saying is that there is no home page specified in the site settings, and the first menu item in the site (after the deletion of the original active home page) was a disabled page which acts only as a navigational placeholder in the menu system ... then I'm not sure you can call this a bug exactly ... it might be something that could be dealt with in core by saying that in the absence of a specified home page, the first active page (whether parent or not) in the menu system becomes the de facto home page.

I would consider that an enhancement, not a bug fix, however. I think it is reasonable that users, in such an instance, should specify the site home page. It can be any page on the site.

I'm curious - what page was expected to load? We talk about sites loading, but really when the site loads, it is represented initially by the first page that appears to the user.