AnnaS is correct
I might add: my last UA-code-share-transatlantic-flights on LH-metal did add to my life-time-miles with UA too - this is probably a bug ... but I don't mind. The reason for the 'bug' is probably UA's rule to count those flights equal to UA flights for status bonus, etc. Those flights did 'qualify' last year (when I was 1K) also for UA's 10'000 miles rule regarding NorthAmerican-upgrade-vouchers ...). I didn't mind either ...