Quite simply, provided your native licence was valid at the time, this case is still pretty straight forward, so long as you or your friend make no drama over the use of the ID.

So far things have followed the correct chain of events:

• Police have contacted registered owner (hire car company)
• hire car company nominate registered hirer (your mate)
• hirer nominated known driver (you)

Once again, if you throw your hands up and face the music over the speeding fine, your looking at a 4-figure fine and probably be banned from driving in Switzerland for 1 lap of the Sun.