In a long duration event like this one, melting, sublimation, wind and compaction ongoing during the event can help maintain a decent disparity between snow depth and total snowfall.
Personally, I am not a trained spotter, but I am a vigilant and am fairly precise while attempting to follow the NWS guidelines for snow measurement. I am long time winter weather enthusiast and strive to maintain accurate records for posterity. Interestingly enough, my personal experience in this storm sounds very similar to what you described above. I measured a storm total of 30.3” at my location. I later learned that a trained spotter from the same municipality reported 30.5” from the event. I also happened to record a time lapse video for the duration of the event, focused on my snow stake which shows 1 inch increments up to 24”. The snow depth at the stake never quite made it to 22”.
While there may be some exaggeration out there and even intentional misrepresentation of snowfall figures, I think most folks on this and similar forums do an honorable job in reporting their totals.