The Union Carbide commissioned Arthur D. Little report concludes that it is likely that a single employee secretly and deliberately introduced a large amount of water into the MIC tank by removing a meter and connecting a water hose directly to the tank through the metering port.
Laporan Arthur D. Little yang ditugaskan Union Carbide menyimpulkan bahwa ada kemungkinan bahwa seorang karyawan secara diam-diam dan sengaja memasukkan sejumlah besar air ke dalam tangki MIC dengan melepas meter dan menghubungkan selang air langsung ke tangki melalui porta pengukuran.