Hmm. I'm not an 'expert' but from the order history, it looks like there was no reason why you couldn't retreat there - no one moved to Portugal that turn. Did it not give you the option to retreat there? Or did it not retreat there by default? Seems odd.

Did you just not put in the order to retreat to Portugal, or did it not give you the option?

In some sites if you had no orders (NMR) then any unit that is dislodged is automatically destroyed. This is usually covered in the House Rules of a Site.
I see no such reference in the rules on this site. So the options are:

1. The computer destroys dislodged units when you NMR, but you are not warned about this or I simply am not able to find it (also a good possibility)

2. There was a retreat, you did not see that you had a retreat and thus NMR'ed again and because of it the unit was destroyed. NOTE that this site does not record in the text files the retreats or whether a player has NMR'ed or simply issued all hold orders or has ordered his unit to be disbanded as opposed to NMR on the retreat to get the same effect.

3. There was a bug and you were not able to retreat to Portugal.

Only Kestas can maybe know for sure,

It looks like you already advanced the game, so it may be useless at this point other than as a bug research.

Just to clarify -from his previous thread, SouthernPride stated that he basically failed to move, but in the retreat phase he input orders for his fleet to retreat from MAO to Por.

What we don't know is - did he put in the order, but not click 'update'. How many times have we all been bitten by that one - you put in an order, then write some press, and the order is lost.

doesn't it usually take a turn to come out of civil disorder? so if you fail to enter any orders, (and some takes over in the next phase) everyone sees you are in CD and know you can't make any orders that turn.

the person who takes over has to wait until the next phase to enter orders (though i'm sure they might lie to other countries to convince them otherwise...)

Nope. A CD can immediately enter orders if there is still time left in the phase. And you don't have to wait a turn after NMRing to put another set of orders in either. I don't know where you got your info from, orathaic, but it is demonstrably wrong.