With introducing the new Coffers rule (they can now be spent anytime on your turn, see forum.dominionstrategy.com (http://forum.dominionstrategy.com/index.php?topic=20909.0)), two cards got errata to prevent some unwanted interactions: Merchant Guild and Patron. Patron now reads:
QuoteWhen something causes you to reveal this (using the word "reveal") in an Action phase, +1 Coffers.
Since you played Loan during your buy phase, Patron correctly (for the new wording) did not give you a Coffers.