I've taken to putting a strap through front wheel and around side-stand if in any doubt of movement - impossible to roll off then...
And yepp, mines the first bike I've had that rolled off side stand... whilst I was stood behind it - fortunately with less damage though.
Straps also good for round centre-stand and front wheel too for ferries etc - again, impossible to roll off.
A small tie-down strap fits easily in pocket etc
Make sure it's 'safe' before you bend down to attach though...or you might save the bike but be pinned to the floor
I know someone who was pinned to his garage wall by an aspendcade and had to scream for help and be rescued by a passer-by before a crush injury set in