Not so, my friends.
This page of Talmud continues the analysis of various kinds of throwing an object on Shabbat between Public and Private spaces. For example, if one catches this object: if the catches stays in one place, then the thrower is liable. However, if the catcher moves from his place to catch it, then the thrower is exempt. Again, intention – the catcher has to demonstrate that it was not accidental.
What about if there is a basket in his hand? Is a basket in a public domain considered a private one?
R. Jose son of R. Juda said: If one fixes a rod in the street, at the top of which is a basket, [and] throws [an article] and it comes to rest upon it, he is liable.
It is not clear if dunking is allowed.