How did this crab get in our house?

For the purpose of treating the crab we found like any other decent crab to have stumbled into our home, we have decided to refer to him/her as Nutmeg. 

Facts:

1. We are on the island of Phu Quoc and our place is about 3km's from the nearest body of water.
2. Our house is surrounded by a 1.5m high concrete wall.
3. The doors were open because we were hot from the day-long power outage.
4. Andy looks super hot and super cool without a shirt.
5. Andy's shorts were purchased at the Cambodian duty-free. Children's size XL.
6. Crab's prefer to walk sideways and seem to be quite slow at it.
7. There is a 10cm high ledge at the entrance of the house. The ledge is ceramic tiled, meaning it is slippery!

Hypotheses:

1. Nutmeg was a victim of domestic violence and needed to find a safe haven.
2. Nutmeg heard we were having spaghetti and decided to join us for lunch.
3. The neighbors were asking: "Hon-ey, con cua o dau?" Which very loosely translates to: "Kim, where the hell did the crab lunch go?"

We didn't quite know what to do with Nutmeg at that frantic moment so we took the time to grab our camera and video tape how things unfolded.

Looking back, we sincerely regret the actions we committed that day. We were panicking and neither of us had any previous experience with such a situation.

Here is our advice for anybody who should find themselves in this predicament. (Note: For household encounters only. Should you find crabs in your pants, please visit your local health clinic.)

1. Fill a bucket with water and sprinkle a tablespoon of sea salt.
2. Gently place the crab in the water.
3. Transport to nearest beach and release.

Please don't judge us.

Signed,

Shellfish enthusiasts