more likely
he is a ruthless ** who doesn't care about people dying and slightly increasing the profit margin is for him worth more then a some people dying
regulators/law allowing self driving companies to wriggle out of responsibility didn't help either
lidar was interesting for him as long as it seemed light Tesla could maybe dominate the self driving marked through technological excellency the moment it was clear it won't work he abandoned technological excellence in favor of micro optimizing profit at the cost of read safety
which shouldn't be surprising for anyone I mean he also micro optimized workplace safety in SpaceX away not only until it killed someone but even after it did (stuff like this is why there where multiple investigations against his companies until Trump magiced them away)
the thing is he has intelligent people informing him about stuff, including how removing lidar will statistically seen kill people, so it's not that he doesn't know, it's that he doesn't care