Probably a bad electrical switch.
I don't know if there would have been a catastrophe or not going down the road and the jacks starts lowering. Electric stab jacks are not that fast and probably they would have hit the pavement and bent backwards toward the trailer frame. You certainly would hear it when they hit though.
I remember one time out West we stopped for lunch at a rest stop and slide the dining room out. After lunch we jumped in the truck and started for the entrance ramp. I look out my side mirrors and ( you guessed it) I forgot to retract the slide. I sure would have been a sight going down the Interstate!!!
Bill B. (S.E. Michigan)
2014 Keystone Cougar High Country 321RES (was 2007 Eagle 322FKS)
2007 Dodge Megacab CTD