Due to the unexpected extended maintenance I had to hurry to use the Buyout option for the final day of this event, but did not have time to choose which character to claim the reward on any of my accounts before the maintenance started.
I had expected it to still appear in the Events tab until I claimed the reward after the maintenance, but nothing shows and the Second Chance option is also greyed out.
By completing but not claiming the reward I appear to have fallen into a crack in the process, in that I can no longer view the option to claim the reward, but despite having completed the event I cannot use the reclaim option to at at least access the pet either.
I have already posted a bug report, but I wondered if anyone else had managed to trap themselves in this way?
The reason I did not claim the reward immediately was that I had not had any problem doing the same with 'Event Campaign II' reward, and even now that still shows on the Event Tab, so I assumed (!) there should not be an issue on this occasion.