Bose malfunction or comms failure

My CFII and I both have A20s. Today we taxied all over DVT at 4:30am on the CTAF (runway closures make it so we have to cross both runways to get to the open run up area) and heard no one making calls. We had previously gotten ATIS so we thought our comms were working. We made all our calls and shortly after we were clear of the active, a PC-12 took off right behind us. We didn’t hear them make any calls. Eventually had to taxi back without TO due to excessive RPM drop on mag check. We called dispatch and didn’t hear a response from them several times, eventually they called CFIIs phone and said they can hear us, but we couldn’t hear them. Maintenance said it was most likely our headsets were coincidentally both malfunctioning, and “9 times out of 10. It’s not the plane.” how likely is it that we just coincidentally had a problem with our headsets and the plane was fine? We could hear each other clearly, and we had the ATIS after start.