Software engineer Don Eyles concluded in a 2005 Guidance and Control Conference paper that the problem was due to a hardware design bug previously seen during testing of the first uncrewed LM in Apollo 5.
sˈɔftwɛɹ ˌɛndʒɪnˈɪɹ dˈɑːn ˈaɪlz kəŋklˈuːdᵻd ɪn ɐ tˈuː θˈaʊzənd fˈaɪv ɡˈaɪdəns ænd kəntɹˈoʊl kˈɑːnfɹəns pˈeɪpɚ ðætðə pɹˈɑːbləm wʌz dˈuː tʊ ɐ hˈɑːɹdwɛɹ dɪzˈaɪn bˈʌɡ pɹˈiːviəsli sˈiːn dˈʊɹɹɪŋ tˈɛstɪŋ ʌvðə fˈɜːst ʌŋkɹˈuːd ˌɛlˈɛm ɪn ɐpˈɑːloʊ fˈaɪv.