It would be more plausible that this guy was a victim of a massive electrical discharge than someone who made contact with a particle beam. Lots of reasons stated above as to why it's highly improbable that the accelerator was operating at all. More likely, if it was recently operating and came off-line due to a system fault, it wouldn't be the first time inadequate safety precautions were taken for faulty equipment that resulted in someone discharging a highly capacitive circuit through themselves. Everything reported in this story has been associated in the past with high voltage electrocutions.