Granted, I haven't had the time to read every detail as you have, but I would think that buying the land in month 5 was the plan at the time. Without looking at the detailed schedule, there aren't any predecessors that come to mind. In other words, they could purchase the land prior to month 5, maybe month 2 or 3, if needed? Schedules should have some flexibility to deal with changing conditions as things progress.
Big Al