Funny, I just remembered that movie my kids loved so much; "All Dogs Go to Heaven". In Lucky's case, she did come out of the grave.
When I got back to the hole in the ground to find her she was staring up at me. She almost seemed a little embarrassed. I don't think she would have deliberately jumped in there; I have to believe that she was running along as she has many times before (oh, there's an old joke about that happening to a drunk...but another time) and the ground suddenly went out from under her feet. I now recall hearing an unrecognizable thud of some kind when I was walking away and Lucky's sudden drop may have explained it.
Thankfully she didn't appear to be hurt, but I felt that haste was in order anyway. (was I worried someone would come along that I had to explain this too?....some grave-robber or Johnny Depp? ) Next to the open grave was a ragged piece of plywood slightly narrower than the opening itself. (a template?) I put down my flashlight and maneuvered the plywood to line up with the grave and then slid it about half way over it. I let the end drop down slowly till it touched the ground below, shining the light again to make sure Lucky was on the right side, then I hopped down in behind her. Yeah, you KNEW I was going to end up in that hole somehow! I gave her a little push on the behind and she scrambled up the slippery plywood ramp and out again and I promptly did the same. Returning the plywood to it's original place we were on our way, pretty sure that if there were any spirits lingering last night, they had a good laugh.
Lucky has not made any requests to go out on a walk tonight.