Presentism and Regret

Bill offers the following argument against presentism,

1) There exist states of regret.
2) Every such state has as its accusative an event that exists.
3) Every such state has as its accusative an event that is wholly past.
Therefore
4) There exist wholly past events.
5) If presentism is true, then there exist no wholly past events.
Therefore
6) Presentism is false.

Bill asks, Doesn't this argument blow presentism clean out of the water?  I'm afraid I can't agree.   I think 'exists' here is being used in three distinct senses: 

a) 'there exist' (1, 4), ie, quantification over items past and present.
b) 'event that exists' (2), ie, is real as opposed to imaginary, say.
c) 'there exist' (5), ie, there are present.

We can rewrite Bill's argument without using 'exists' as follows:

A. There obtains, now, a state of regret, r.
B. There has occurred a real, wholly past event e, the accusative of state r.
C. There have occurred real, wholly past events.
D. If presentism is true then no wholly past event is occurring at present.
E. ???

But A to D are not inconsistent.  I would say they are entirely 'Moorean', as Bill would say, and are expressed in everyday tensed language that we all understand.  They make no metaphysical claims. Where, exactly, is the problem?

The only possibly problematic aspect I can think of is that we allow that the state r and event e be diachronic.  Bill may feel that for e to be the accusative of r, e and r must be synchronic.  E must be 'there' for r, as it were.  But that would need justification.  Bill would say that, under presentism, the event e 'is nothing', by which he means that e is not and never was anything at all.  This overstates what the presentist claims.  He certainly agrees that the event e is not ongoing.  But he does not agree that e never was.  He would probably want to tell a causal story in which the event e leads to the state r and may well have ceased to be ongoing before r comes into existence.