The incident you are taking about was actually staged in that the photograph(s) were taken several days after the battle of Berlin. As, "At 14.25, Maj Gen V. M. Shatilov (Commander, 150th Rifle Division) reported that he thought he had seen a Red Flag over the steps of the Reichstag near the right-hand column. As the leading battalions contained a number of groups eager to have a go at planting a flag on the Reichstag, including a group of volunteers from Corps Headquarters under his aide, Major M. M. Bondar with the 380th Rifle Regiment and some gunners under Captain V. N. Makov with the 756th, this report did not seem too unlikely. The wild enthusiasm with which the report was sent resulted in Zhukov issuing Operation Order No. 6 of that that read "Units of the 3rd Shock Army . . . having broken the resistance of the enemy, have captured the Reichstag and hoisted our Soviet Flag on it today, April 30th, 1945, at 14.25 hours." (Le Tissier, p. 168) This false report was sent to Moscow and abroad but when war correspondents converged on the Reichstag, they found Soviet infantry had only advanced halfway across Königsplatz. Aware of his error, Shatilov ordered his division to raise a flag or pennant on the building, whatever the cost." At appromimatley 18:00hrs "finally, the special banner party with Red Banner No. 5 containing Sergeants M. A. Yegorov and M. V. Kantaria managed to find their way around to the rear of the building where there was a stairway up to the roof. Finding a mounted statue, they wedged the staff of their banner into a convenient crevice and thus the Red Flag, at 22.50 on 30 April 1945, finally flew over the Reichstag (Red Army Target No. 105)"
Another account of the same incident:
"It was Red Banner No.5 of the [150th Rifle Division] 3rd Shock Army…[it was] twenty-three-year-old Capt. Stefan Andreyevich
Noystroev…men [who eventually] battled their way into the building, fighting for every room and corridor…Noystroev ordered a shock detachment commanded by Lt. Berest to escort the two [Zinchenko appointed regimental] standard-bearers…[who] took nearly half a day to reach the dome. At 10:50 P.M. on April 30, the banner of victory was unfurled over the Reichstag. From this account it becomes clear that the famous photograph [by Khaldei] of [standard-bearers] Egorov and Kantariya planting the Red Flag on the roof of the Reichstag could not have been taken at that historic moment. For a start, it was dark at 10:50 p.m., while the picture was obviously taken in broad daylight. Moreover, the soldiers in the street appear to be moving about quite fearleesly and openly, which they would not have done had fighting still been going on all around them-as it was at the time the banner was first held aloft. If we look more closely, we see that there is no trace of anything on the vulgar pinnacle of the Reichstag to which a flag pole could have been attached. The soldier is simply holding up the flag in a dramatic pose. In other words, the world-famous photograph must have been taken a day or two after the storming of the Reichstag." (Kuby, Erich. The Russians And Berlin, pg. 60)
As for the 150th Divison it appears that as of 2004 it is the Military Training Center for the Transbaikal Military District. (V.I. Feskov, K.A. Kalashnikov, V.I. Golikov, The Soviet Army in the Years of the Cold War 1945-91, Tomsk University Publishing House, Tomsk, 2004)