I am a man that wears many hats as most of us on this forum do. 1 hat is that of a locksmith. Medeco which I do use around the car wash for the vacuums and such is a great lock no question about it. They use to offer something like $10,000 if you can pick any of there locks. Well I saw one picked right in front of me. We thought it was a fluke and gave this guy 2 others to pick and he did them as well. These were padlocks. I was shocked. ASSA is a great lock. They have a really nice strong sidebar inside the cylinder. Never saw one picked.....ever. Thats what I use on my house.When you question did the locksmith take it, the story sounds like he was just there. There are locks that are easy to pick or watch youtube for lockbumping.
Tell us more about what was picked.. I will add that in our state of ND my daughter needs a license to cut hair, but a locksmith doesn't. We need more info to help, but there are plenty of pickproof locks--Medeco-ASSA-
Are you sure they opened the vault or is that your conclusion because they were empty.