I would like to report a BUG. Please check game #174047. I had a scoring card in hand and North Sea Oil was in effect so I could play an 8th action round. It was my intention to play the scoring card in the 8th action round, but the app decided to already end my turn after the 7th action round and then the app said I lost the game because I was still holding a scoring card!!
That is why I now rate the app 1 star in Google Play. I will give 5 stars again after the bug is fixed. Thank you in advance.
EDIT: My bad, apparently North Sea Oil was played in the previous turn. Still it could be made clearer, as gweis also writes (see below). Compliments for the speedy reply!