Although there are not as many smokers around as there used to be, a smoker would probably carry a lighter, (most non-smokers do not) not matches.
Most engineers I have known are gadget freaks, too. Especially the Mech Engineering types, more likely to find the neatest igniter gizmo they could, as long as it is reliable. Although I guess that might include matches, too.
Does anyone have a picture of the bench after the explosion? Scorch marks on concrete, fracture patterns, embedded objects (even miroscopic ones) etc. might shed more light on this (which is one of the reasons to remove it, as well as for chemical testing).