1. Is the drone pilot Part 107 federally compliant?
2. Does your drone pilot hold a Remote Airman Certificate?
3. Are you insured?
If they answer NO to any of the above, they're not compliant with FAA Part 107 for flying or operating a drone commercially. If you hire a drone pilot that is not compliant you could be at risk. You may be held liable if an unfortunate incident occurred and the drone photographer/pilot was flying illegally.
Any drone pilot/photographer is required to have a Remote Pilot Airman Certificate to fly commercially, and it must always be kept current. —You should minimize your risk. Always ask the drone photographer about this before you get and estimate and or start any project with them.