Oh yeah, I totally forgot about that one (the aftermath being perhaps the start of CRM/human factors, of course the DC-8 in PDX 6 years later, is what which cemented the path to CRM...)
I suppose you could call a light bulb part of a system, and in that case consider it something that led to an accident (perhaps, more correctly, a factor), but I'd say in that circumstance it is certainly not not attributable, like a faulty cargo door handle leading to a door failure, leading to the floor failure, the total hydraulic failure, etc. (Paris, 1973).