Continuing on the knife note, I remember hearing the following from a 4th dan addressing a steakhouse table full of aikidoka ranging from the most junior up to 1st kyus:
On the street if he's got a knife, chances are you ARE gonna get cut. BUT, you can try to control where and how badly. It's better to take superficial wounds to the outside of the forearm than a penetrating stab to the abdomen.
Of course, to the horror of other restaurant patrons, there followed a table full of aikidoka going through the motions with steak knives from the table.