You have my sympathy. I hate loaning tools to non-tool-savvy people -- especially tools I care about.

A sharp file can easily reshape 420 stainless, which is the knife steel in the standard Wave / Wave II. As long as you don't put it on a power grinder, you won't do any harm.

If the hinge and lock work acceptably, things will probably get back to normal after a bit of use. However, don't hesitate to send it to Leatherman customer service; they've seen worse, and repaired it without hassles.