The initial charge pressure will change as the house temp drops. If the house was hot when the ac was pressurized the pressure will change once the inside temp drops. Once the heat load is less, the low side pressure will drop and more freon is gonna need to be added. Here in the south the inside of the house can get extremely hot when the ac goes out. Here in my neck of the swamp the unit needs to get the furniture and everything cooled down then the pressure needs to be adjusted again. Get him back out there to check it is what I would do.