I guess you're sayin you gave up yer old habits. I heard Gary still misses you! No matter what any investigator says, it's impossible to fire a 1911 unless the safety is depressed and the trigger pulled. I saw incidents in the Army that claimed the same thing, but no way to fire one unless both are done at the same time. (Snowflake) :grin
That link you posted mentioned the trigger being fowled by the clip, but no mention of the grip safety. I'd say as in most misfires someones bugger picker was involved.