Very interesting. It sounds to be like two different agents dealt with the two passengers. One realised that they wouldn't have been able to disembark before 22:31, as it is impossible to get everything in place within two minutes after the aircraft has arrived on stand and therefore paid the full compensation. The other agent probably hasn't realised this and has only paid 50% of the maximum compensation. So I have sent them a message with all the timings and told them exactly what to say and do.