Yes, and it happens all the time. One of my houses had been over-valued tax wise for years, but I was reluctant to "get on their radar", figuring they would just "get me back" on the acreage it was on. Then, two years ago, they bumped it another 30K (just the house) and some "out buildings" doubled. After contacting the county's guy, all it took was sending him some pics, and he reduced the house value by 100K .... he was awesome and it was painless.
That was in a more rural county .... my houses (two I recently sold) that are "in cities", shot up in tax value last year, but still lag behind the "real market value" by a significant amount. Shhhhhh ...
Good luck!