As per Google Earth terrain data, the terrain dips down to approx 180m MSL between ДПРМ (compass Locator at Outer Marker, LOM) and БПРМ (compass Locator at Middle Marker, LMM, where the aircraft first impacted a tree). With the field elevation at 262 meters, it is possible to have 60m on RA and be below the field.
According to all the drawings and data published on the Smolensk forum, the lowest point is at 202 m.
Now, tha latest news. When they went below the 100 m, as was already said, the counted 90 m, 80 m... etc They counted down to 20 m. Taking into account the topography, it means they were descending using RA.
Another point, just my guess.
I belive, they could have mixed WGS-84 coordinates and Pulkowo coordinates. So far MAK was slightly enigmatic on that just informing that they didn't have the actual data (NOTAM, etc...). MAK wasn't very specific here.
Second option is a scud run.
Arrakis