I have no idea. If it was not Hartmann, then probably ground fire. (At least I am not aware of any other Yak claims in the area by Axis fighters.) Small calibre fire during strafing usually meant flak (ground) claim. Ground victories (especially in the final months of the war when Axis Air Forces lost their power) were very common. In fact most of soviet planes were downed by flak, especially the ground attack planes operating in the favourite altitude of German flak batteries. But soviet AAA units were also very successful. Their gunners were famous for being very dangerous and accurate against low flying planes. An interesting story for those interested in Soviet AAA operations:
In the final moments of the battle for Budapest, on February 12, 1945 a Hungarian Bf 109G was downed by soviet flak near Tököl, Budapest-S. (Bf 109G, marking: W-1+61, engine: DB 605: 00707595, piloted by 20 yrs. old Corp. Tábori Sándor. (
In soviet report: 18 yrs. old) Plane was downed by Soviet 1614 aer. polk PVO from the distance of 800 m, at the altitude of 300 m. For downing the plane, the four 37 mm AAA cannons fired 65 rounds, while the escorting 12,7 mm DSK-machine gun fired an addition of 12 rounds. The plane got hit and belly-landed on the shore of the Danube. The pilot was captured, beaten badly, his eye got injured, stripped off his clothes and right before being shot on the spot, a merciful Soviet officer arrived, who stopped them and saved his life. (Others were not so lucky...) He was handed over to the 4th Gv. Army. The case was confirmed by the HQ. of the 715 ShAP, stationing on nearby Tököl airfield. (ЦАМО, фонд 17 ВА, опись 6568, дело 57, л. 46) In captivity Tábori got lung-desease that followed him for the rest of his life. He survived the war and later joined the new Hungarian Air Force that he had to leave in the '50s, due to typical, false charges during Communism against the 'old-era officers'. He became a driver and a teacher-engineer. He passed away in 2001.
See his pic.
Gabor
See also:
http://www.roncskutatas.hu/node/10862