It's also been documented that the extraordinarily eerie, flat calm conditions of that night contributed to the inability to spot the berg.
Ah, but it WAS spotted. The problem was that the captain had ordered top speed through a known ice hazard area, so by the time it was spotted, there was no time to miss it.
Ironically, had it impacted the berg dead-on, it would not have sunk.
Which was probably the idea behind the whole set-up, since the "Titanic" that sunk was actually the Olympic that was previously damaged. Had it smacked the berg straight, the forward sections would have crumpled but the ship would not have flooded over the sequential compartments that the side-rip allowed. Then the claim that the ship was "unsinkable" would have been proven, and they would have collected the insurance money for the "Titanic" for icebergs that they couldn't have collected for the Olympic simply smacking into another ship through negligence.
But they had really GOOD lookouts that night, who were on the ball and spotted the berg JUST far enough out to avoid a head-on collision, and enable the slow turning of the ship to juuuuusst rip along the side...