I've got a difficult time believing that ONE tank can fire that fast and hit 3x in the exact same spot - at least back in those days when the gun was laid manually. One tank shooting that kind of group AFAP under stress?? I don't know about that. It's hard enough to do that with a rifle never mind a tank gun. That said, you're the tanker, not me. I was Field Artillery.
The Panther might have been stationary, in a fixed position or immobilized.
The war diary of 3rd County of London Yeomanry (Sharpshooters) for the time reports an inspection of a destroyed Panther on 21 June 1944 (which does not appear to have involved that unit) and then an engagement on 10 July involving seven Panthers (six of which were destroyed).
The war diary for 4th County of London Yeomanry (Sharpshooters), however, reports that on 11 June 1944, they encountered two Panthers, one disabled on a road and the other providing cover. 2Tp C Sqn flanked and destroyed the Panther, while infantry destroyed the second Panther with PIAT.
(Note that these units were later combined in August 1944 to the form the 3rd/4th County of London Yeomanry (Sharpshooters)).