Deleting 2nd to last point causes a null pointer exception to be thrown. I also duplicated this issue using https://github.com/ThinkGeo/DrawEditFeaturesSample-ForAndroid with the latest 10.5.x android code. Using the sample above a placed a line with 2 points and then went to edit mode and attempted to delete one of the points
I have not verified this but I was told that this issue also occurs in the iOS version as well.