That's assuming that this was an individualistic act of sabotage - that the information gathering and execution of this stunt was the action of an individual. How do you know that? The fact that the narrative of the event was widely known seems to suggest there was at least some workplace-level complicity.
As for political relevance - the political relevance of the refusal of work should be obvious, if you consider relations in the workplace from the point of view of valorization. Simply put, while your wage buys your labour power, not your labour. Tapping surplus value out of a worker requires the valorization of the 'variable capital' (i.e. purchased labour power) put out by the capitalist. The 20th century saw a transition which is important here - a transition from the extensive (i.e. through longer working days) to the intensive (i.e. through more 'productive' labour) mode of extracting surplus value.
This transition has made the workplace struggle around the valorization of capital that much more important (as chronicled by various authors, including Gramsci in 'the American worker', C.L.R. James in 'Facing Reality', etc.) and correspondingly the capitalist ideology of personal productivity, identification with the job, etc. is that much stronger. In so far a workplace culture of resistance to the process of valorization is certainly political. Of course, this transformation happened largely after the heydey of the IWW, so their commentary on it is notably lacking.
Then, do events like the slashing of the boss' tires discourage political struggle? While sometimes they might act as simple venting, if you examine the act as part of a process - the process of the workers in the workplace clarifying the relationship between themselves, the boss and the job, then this act is not necessary depoliticising. (Consider for instance, that in the course of period of heightened class struggle, such as a strike, many 'individual' acts of sabotage, etc. tend to happen. These things are, in my experience, both an expression and a reinforcement of a culture of militancy)
I think it is politically important to recognise that these things are happening outside of the context of traditional working class organising - in fact this 'micro politics' of the class struggle is often an important part of setting the context for the visible features of the class struggle.
Peter -- Peter van Heusden <pvh at egenetics.com> NOTE: I do not speak for my employer, Electric Genetics "Criticism has torn up the imaginary flowers from the chain not so that man shall wear the unadorned, bleak chain but so that he will shake off the chain and pluck the living flower." - Karl Marx, 1844 k*256^2+2083 OpenPGP: 1024D/0517502B : DE5B 6EAA 28AC 57F7 58EF 9295 6A26 6A92 0517 502B