I haven't seen these bouncing shots in RO yet. But then, they didn't really happen in reality too. You can safely place this story in the realm of mythology....
I know of these stories, but they are really just legends.
Say what you will, but even if it is physically/kinetically improbable that it would work, the fact of the matter is that some tankers tried to do it.
Maybe it never worked, but the mythology, as you put it, was present on the battlefield and strong enough to make gunners try it.
Facing a Panther head-on, I'd probably also try just about anything, too out of sheer desparation.
And oh, BTW, they also used white-phosphorous shells on heavy German tanks, in the hope that they could ignite the engine fuel.