(a) If the exercise of a power is improper, the guardian is liable for breach of the guardian’s fiduciary duty to the minor or disabled person or to interested persons for resulting damage or loss to the same extent as a trustee of an express trust.
(b) The rights of purchasers and others dealing with a guardian shall be determined as provided in § 13–219 of this subtitle and are not necessarily affected by the guardian’s breach of fiduciary duty in the transaction.