According to the in game information I wouldn't say that this statement is entirely accurate. The 76mm gun on the Sherman will penetrate 134mm/115mm/97mm at 0, 1k, 2k respectively. Not counting the turret the thickest armor on the Panther (again using the in game data) is 80mm. I'm not factoring in and angle of impact here and those penetration values are at 0 deflection but what you described as happening doesn't sound that far out of reach at all.
Of course there could be a bug, but depending on angle, range and where the round actually hit damage may not be as far fetched as you'd think.
None of the armor on a Panther is 0 degrees, and we all know what sloped armor does: it "increases" armor thickness and increases the chance of a deflection. Regardless of where it hit, the impact was not perpendicular vertically or horizontally. The pics I posted show exactly the angle it hit horizontally, and the vertical impact would not have even allowed the point of the projectile to connect with the armor, so it "should" have been a glance shot, I believe.
I would have not brought it up if I didn't think there was a legit reason, but at that range the Panther should only fear the Tiger, Firefly, or another Panther. Just a few days ago I had a spawn "camped", if you will by performing a blocking action between their spawn and town. I sat out in the open, 2400 yards + from their spawn. They upped M4A3/76mm, Panzer IV's, and T34/85. I was taking round after round after round and the Panther shrugged them off. As I watched the film, I counted 22 enemy tank hits on my Panther, and I ended up with 8 kills. THAT is what a Panther should be able to do. So the 2800 yard miracle shot to the tread makes me go
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