Well, they don't actually ponder, I do :)
FIFA's schedule states the deadline for matches to be included in the ranking calculation is on the Thursday prior to the release date.
They usually include matches played after the deadline, especially competitive matches. However, last month they've also included a friendly played on Saturday, 25 June: Kenya - Sudan 1 - 2.
Liberia defeated Gambia on Sunday, 24 July, but FIFA chose not to include it in the July ranking calculation. If this match would have been included, Gambia would have dropped from Pot 3 to Pot 5 (and forced to play in Round 1), while Mozambique would have taken their place.
See the official CAF pots.