Question for the pros!!

I have hired a tech. to install a new 2 ton cond. unit and a new 2 ton a-coil. I know that he has tested the line sets and evac. them, by the way he also has had the test on for not only hours but days. The problem he is having is that when he goes to charge the unit with freon he can't get the liquid side pressure up to where it needs to be. He claims it should be around 65 and it only will go up to like 18. Any ideas?