Such questions as these (though not precisely the above example) are discussed by Billy Clark in his paper Relevance and 'Pseudo-Imperatives' (Linguistics and Philosophy, Vol 16, 1993). He begins with four illustrations of the pseudo-imperative: Come closer and I'll give you pounds 5; Be off or I'll push you downstairs; Come one step closer and I'll shoot; Open the Guardian and you'll find three misprints on every page.
Such 'conjunctions or disjunctions of an imperative and a declarative clause' create problems for most semantic theories if they are to be considered as imperatives. 'As is true of most, if not all, utterances,' he explains, 'an utterance of any of the four is open to a wide range of interpretation.' The crux is whether the speaker wants the state of affairs in the imperative clause to be realised.
'To utter an imperative with propositional content 'P' is to communicate that 'P' represents a thought entertained as a description of a state of affairs in a potential and desirable world,' says Dr Clark. 'In each case, the hearer has to make some assumption about how desirable the state of affairs is thought to be, and from whose point of view it is thought to be desirable; in making these assumptions he is guided by contextual factors and consideration of optimal relevance.'
Also important is the notion of potentiality: an imperative, to be taken seriously, should describe a state of affairs that is not merely possible, but potential. Thus 'turn into an earwig' is cited as an unrealisable imperative, which is 'not acceptable in normal circumstances'.
A vast array of questions must therefore have formed in the punk's mind when deciding how to react to the pseudo-imperative. Was the making of Clint's day a realisable state of affairs? With doubt about the number of bullets remaining in the chamber of the gun, there was no definite answer, although the state of affairs of Clint's day having been made would clearly not have been in the interests of the punk, since his head would have been 'blown clear off'. Such a consideration must be deemed a contextual factor of optimal relevance.
All this, however, still does not explain why the hearer of a pseudo-imperative is sometimes persuaded to attempt to bring about the states of affairs described. 'It is only when we introduce something like the notion of desirability that we begin to approach a satisfactory account.'
The issue is further confused by the question of whether the pseudo-imperative is genuine. 'Miss this train and you'll never get there on time' or 'catch the 'flu and you can be ill for weeks' are 'neither imperatives nor conditionals but belong to a distinct class which has elements in both'.
In these circumstances of semantic confusion, it is hardly surprising that the punk surrendered meekly.