[OSM-legal-talk] odbl use case questions

[David C.]

I've looked at the Odbl but can't quite get my head around it; I'd
like to get input on a couple of use-cases:

An organization (US tax-exempt non-profit) operates a UMN mapserver to
provide public parks information.  They use a shapefile generated from
a filtered snapshot of OSM data--leaving only roads--as a base layer.
Obviously they will have had to work with the shapfile table schema to
create their visual formatting.

If they do nothing else but serve this one-time snapshot as a base
layer, what are their obligations?

Secondly, what if one of their staff, being unfamiliar with OSM but a
GIS expert, sees a problem with one or more roads about which they
have personal knowledge, and "fixes" those problems in the GIS data
only--then publishing the result as a mapserver layer only.  What are
their obligations in this case?

Thanks.