Slotin was an arrogant ass. per wikipedia: "Under Slotin's own unapproved protocol, the shims were not used and the only thing preventing the closure was the

Slotin was an arrogant ass. per wikipedia: "Under Slotin's own unapproved protocol, the shims were not used and the only thing preventing the closure was the blade of a standard flat-tipped screwdriver manipulated in Slotin's other hand. Slotin, who was given to bravado, became the local expert, performing the test on almost a dozen occasions, often in his trademark blue jeans and cowboy boots, in front of a roomful of observers." play stupid games, win stupid prizes. his only salvation was that he sacrificed himself to save his colleagues. there were also other, safer ways to do it "Enrico Fermi reportedly told Slotin and others they would be "dead within a year" if they continued performing the test in that manner."