During the ninth mission (The Seer, The Trickster, And the Brute), where you play Eldar and have to move your base constantly around the islands before you get smashed by roks, the roks somehow destroyed the main base building even though it had been moved to safety. It was right after I had to destroy a bunch of scrap and Killa Kans. The base building was in stealth cover on a safe island, but it still got destroyed by the roks.
The building was placed as close to the other island as possible, and the game regarded it as a safe spot... until it didn't and threw a rok on it.
Lost the mission because of it and had to restart. Pretty ++heresy redacted++ annoying, considering that mission takes a long time to complete.