Given the amount of surveillance and satellite tracking blanketing the globe; how can 'someone' possibly send a rocket all the way to crash into the Moon, without anyone noticing, until after it got there?<p>Sounds like bollocks to me.
It bounced. If the structure was pressurised stable form, it was springy once unpressurised. Or maybe, it calved in-flight. Outgassing or explosive failure of something like a pressurised attitude jet, or a fuel cell with volts