Past exam of the mathematics course of the University of Cambridge / 2023 / iii / Paper 207 / 5 / x / Solution

Yes, a selective update would invalidate the answer to part viii: A's censoring time would be extended because A died, while follow-up for other patients remained truncated at month 24. The resulting censoring mechanism is informative. A uniform update of every patient to the same later administrative cutoff would preserve independent censoring under the original entry-time assumption.