Who chooses the notario for a Real Estate transaction?

A recent addition to the MLS listings for Ajijic contains the following in the description: "(The closing for this property will take place with Notario #1 of Ixtlahuacan at the office of Guillermo Martinez Cuen in Chapala.)". I have seen a few other listings with a similar designation of which notario will do the closing. I thought the notario to be used was the choice of the buyer, not the seller. Can someone who knows please clarify. TIA.

Usually the buyer chooses the Notario however if it is stated as a condition of sale.........then don't buy it if you are unhappy.

It could have something to do with the property status such as the sale of the property being a result of the death of the owner. The notario may be tasked either by the beneficiaries or by the will, to dispose of the property. The notario likely has all the paperwork in connection with the disposal of the property it would not make sense to have another notario deal with the disposition.
I don't know of a sale by court order is possible here, but that may be another reason why a particular notario is to be used.

Quite often one or the other of the real estate agencies has their own preferred notario, because they regularly do business with him/her and the've learned each other's ways. But it is generally not a condition of the sale.