Was Whitehead a Determinist?

I believe he was a determinist. It seems to me that his
"Ontological Princple" is a claim that eveything has a cause. "Actual
occasions" are causes, and are caused. Why could this be controversial?
Whitehead also believed there were "purposes" or "Final Causes". Often
determinism is associated with mechanical mechanism (no purposes). Whitehead
thought it might be that matter in some environments (e.g. living beings
might obey different laws [note still obeying laws]), than in  other
environments. He also speaks of the "determination" of "decisions". I saw
no mention of randomness in the chapter on quantum mechanics in
_Science and the Modern World_, and "random" is not in the index of _Process
and Reality_. Probability is discussed in _Process and Reality_, but it
seems to be epistemological not ontological. The word "indetermination"
is used in _Process and Reality_, but seems to be regarding what Russell
called a "propositional function", and Whitehead seems to call,
less precisely, a "proposition". A variable being indeterminate in
a propositional function and a proposition deing deternined when the value
of the variable in the propositional function  is decided. Now, I think
it is true that complex stuctures can obey new laws [without disobeying,
or breaking] more fundamental laws. E.g. If my cars is moving, and I press
the brake, it slows. This is a new law, although no more fundamental law
is broken. I think this is a simple case, and, for Whitehead, life and
final causes were just more complex instances.

[I think Whitehead wrong about this, as I have discussed elsewhere.]