Some ships released by Mothership on Arcturus not giving RU's

Hello,

Some of the ships that are released to attack my ship in the Arcturus system (Big Orange Star) aren't giving me RU units after the battle.  (I guess they are remote controlled scavenged ships but if they can go into battle they should have some RU units attached).

I played the game t'il the end but never found out what what those ships were.  Nor did I figure out those weird ships whose Captain only says Mmmmmm in a hail.

Thanks