So in the sentence we have an active verb form threw with two objects a stone and at him. The verb is transitive, having a direct object (a stone)...They threw a stone at him.
I tried to transform this "active" sentence into "passive" ones by changing the subject and using a passive verb form:
And I wonder too whether the second sentence/way is correct/possible/used...1) The stone was thrown at him.
2) He was thrown with a stone (?).
(Did I reconstruct them all right, Belly T?)