This video is a little confusing because all of the graphics show daytime conditions. But at one point ATC says that 'we've turned on all the lights, you should be able to see us'.

So I'm thinking that this incident was at night, and that is why the pilot did not want to land off airport.

Can you fly motorgliders at night if you have PPL-SEL+glider ratings? I know that some of them have lights and electrical systems.