That's not what the Wikipedia links says: "A number of potential trigger types were investigated, including software bugs, software corruption, hardware faults

That's not what the Wikipedia links says: "A number of potential trigger types were investigated, including software bugs, software corruption, hardware faults, electromagnetic interference and the secondary high energy particles generated by cosmic rays. Although a definitive conclusion could not be reached, there was sufficient information from multiple sources to conclude that most of the potential triggers were very unlikely to have been involved. A much more likely scenario was that a marginal hardware weakness of some form made the units susceptible to the effects of some type of environmental factor, which triggered the failure mode." Cosmic rays would be a very convenient excuse. (Cue the ECC RAM lobby, which will probably downvote this.)