Presumed Resulting Trusts:
If both people have provided the money, but the title is held just by B then it will be presumed that A & B will each hold a share in proportion to his or her contribution. Equity presumes in the absence of a contrary intention that the person who provided the money intended to retain the beneficial ownership. Presumed resulting trusts rely on a presumed intention.
Automatic Resulting Trusts:
Arise, independently to the settlors intention, when an express trust does not dispose of the entire beneficial interest. (Equity hates a beneficial vacuum). Here the beneficial interest was not completely disposed of so it went back to the settlor on resulting trust (and he got whacked with a tax liability).