Here's the story from the book (yes it is completely possible that this is only a "fishermans story", as we say in Finland, eg. a "little" bit exagerrated,
" Guard rushed into the shelter to announce that enemy tanks were on top the shelter.
We ran out and the sight was agonizingly horrible. A gigantic tank was in front of our gun, driving towards it about 50 meters away. Behind it came three more tanks. Murtojärvi, Vaasala and I ran to the gun, but others did not have enough courage. We shot at the approaching ugliness. First shot was a miss. Second shot cut a track. The tank rotated, thus our third shot penetrated its tower. The tank started to go around us driving in a wide arc and the three other tanks followed it. After a moment the lead tank drove into a hole made by an aeroplane bomb and fell in it. Other tanks continued towards our troops positions behind us. We tried to move our gun to completely destroy the lead tank, but the ground was so difficult that we could not move the gun there and we did not have enough strength to carry it over the obstacles.
Other three tanks now turned back, and their return trip turned out to be their final fate. We shot every one to fire. And there rarely was a day in Summa without fireworks or bonfires, usually provided by the gun company.
We told infantry about the tank in the bomb hole. During the night a demolition squad arrived. But before that the tank crew had escaped through the bottom hatch in order to move to their own lines. But it so happened that a guard saw the escapees on the barbed wire fence and opened fire with a submachine gun. The result was ten fallen enemies. Only one man survived to tell the story. So it could be surmised that the tank had a crew of 11 men. This amount of men tells that this tank was not the size of an ordinary tank. It was so large that Kalle Murtojärvi, who was a man of average size, could only reach the top of the tank track by standing on his toes."