A government UAS pilot reported they learned after flying they flew in controlled airspace without authorization.

Narrative

My department has a drone unit and I am on this drone unit with a department-issued drone. I arrived on scene last and I coordinated with Person A who had arrived on scene first. Department policy and compliance with FAA regulations require us to check for authorized altitudes using the 'Air Control' app. This app is also used to get LAANC approval when required. I spoke with Person B [Remote Pilot in Command] and asked what altitude we were authorized to fly up to. They advised that we were good up to 400 FT. AGL as we were just outside airspace that required approval to fly in. I trusted them and flew my sUAS as did the other drone pilots. I flew to a maximum altitude of 396 FT. AGL during this flight. After we had left the scene Person C called me and advised he checked the 'Air Control' app after he left. Person C advised that it stated that we were not authorized to fly at all due to its proximity to the airport and VOR facility. I looked at the app and determined that this was correct and we should not have flown without the proper approval. In future flights; I intend to check the 'Air Control' App myself to verify what I have been told by others.