If a trustee of an express trust which includes property subject to a power of appointment or other power of disposition distributes such property to those persons who would take such property in default of appointment and such distribution is made not sooner than six months after the death of the donee of such power and without knowledge of the existence of an instrument exercising such power, he shall not be responsible to the appointee under the instrument exercising such power.
C.R.S. § 15-1-202