I think it's more likely that corners were cut with the Millennium Tower, or the engineers made an error of some kind.
None of the other big buildings in SF are connected to the bedrock. None of the towers in LA have supports connected to the bedrock. Heck, the Burj Khalifa isn't connected to bedrock. They all use friction piles, and these can work fine if they're done properly.
I stand corrected! I got my information from a soil scientist who was explaining that the bedrock wasn't anywhere close to the surface in SF and LA and misunderstood that to mean that none of the towers went all the way down. I stand by my claim that the Burj Khalifa isn't on bedrock, however.
None of the other big buildings in SF are connected to the bedrock. None of the towers in LA have supports connected to the bedrock. Heck, the Burj Khalifa isn't connected to bedrock. They all use friction piles, and these can work fine if they're done properly.