I'll be surprised with whoever is the mole. I suspect them all but can't really pinpoint one.

And as for the coalition stuff, the mole is paid to DECEIVE the others, so lying to others in a coalition is perfectly acceptable. The goal of the mole is to deceive the others and make them all think someone other than the mole, is the mole. So is the mole creates a coalition with someone else, they can easily get rid of that partner by lying to them and if they are smart about it, the coalition is kept secret and no one knows the mole got rid of that player by deceiving them.