Saved version of a model appears different from version currently open

[david.g...@harpethhall.org]

I have a student who is working on modeling a soccer goal we will soon be building. She has open, in a Chrome tab, a model that looks like this:

The model is saved (at least, there is no star in the tab name)

When she opens the model in a different tab, though (thank goodness she checked!) she gets this:

The link is http://www.3dtin.com/zh1r , and I also see the severely disconnected version when I open it. I downloaded it as an STL, and same thing. Any idea why this might be happening? Something to do with grouping, maybe, since the whole thing is grouped into one big group?