Would there be a difference between a stone falling due to the wind moving it and my intentionally making it drop?

Unless you are intentionally personifying the wind and giving it an objective of making the stone hit the ground, the restrictive argument would say yes, there is a difference: if you dropped the stone intending that its goal is the ground you could say pumlI' (or pumtaH); if the stone fell off a cliff because of a gust of wind, you could only say pumtaH.

The non-restrictive argument would say there is no difference: the agent's intentions are not described by -lI', the speaker is merely describing an action progressing toward a known stopping point. A rock pushed off a cliff by a gust of wind could be said to be pumlI' because it is making progress toward the known stopping point of the ground.

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SuStel
http://www.trimboli.name/