Check my other thread....
Check my other reply on the Lear Mexico City Crash thread for my explaination about LR-45 Flap/Spoilers. Yes, if you ask Bombardier, they will advise you that assymmetic spoiler retraction is "not probable", especially after a service bulletin of a couple of years ago, BUT ask any Flight Safety LR-45 instructor, and thy will tell you that there have been a least 3 reported cases of it actually happening. In fact, they will run the scenareo in the sim for you, as they did for me. Very aerobatic! As such, SOP's for the spoiler application and retraction is "slow and deliberate". This is a rather early serial 45 (#028), maybe it didn't get mod'ed, coupled with a fast hand on the spoilers as they hurried to 'go down/slow down'.......