TOPIC: CPM in the Sequence Activities module

Hello all,

I have a question about the AON in module 06.03.2, specifically the CPM at approx. 16 mins of the lesson

It's my understanding that when calculating ES/EF, you always do the critical path first, once completing all paths, then you can perform the backwards path

In module 06.03.2, it seems to me that the ES/EF for "F" should have been calculated on the critical path of which is A-C-E-F. So ES for F = 16 (not 11)

Am I missing something?
Thanks in advance
Rick