Even though some "immigration officials keep approving your entry into the country under a tourist visa" it apparently only takes one immigration official to deny your next entry...which means your detention (or "arrest" if you prefer the term) and subsequent deportation.
If I understand correctly, that can happen at the sole discretion of the individual official and does not require approval from the official's jefe.
I understand now. Thanks. Just being detained for some hours before the next flight out, doesn't sound so harsh. When I heard arrested I was imagining getting thrown into some jail or something. Well I'm glad those days are over for me.
Malteaser1, I hear the border is pretty porous with the neighboring countries if you get desperate...but then you really may get arrested!!