In response to a question about how I could have cut myself on the blender blades, here are some pictures of the blender in question. (I took some painkillers, so forgive me if I wander a bit.)

The blender comes in three parts, the base, the blades, and the container.  Unlike a traditional blender, there is no way to put anything in the blender if it is screwed together (there is also no way to use a spatula to get stuff stuck to the sides loose).  The parts screw together, and the motor is not supposed to come on unless the blades are locked on the base.  Unfortunately, there is no lock on the container to stop the blades and motor if the container is not attached.

When trying to remove both the container and the blades, only the container came off.  This made a big mess, and may have been what caused the blender to come on when I tried to remove the blades.  That is the only explanation I can come up with because I know I didn't touch the power button.   I was lucky in that I was trying to avoid the blades when I was trying to unscrew the blades, or I could have gotten hurt much worse.

This is how the blender looks when it is screwed together:

This is how the blender looks when all the pieces are apart:

This is how the blender should come apart after blending something so nothing falls out:

Unfortunately, this is how it came apart after I tried to blend the tuna and mayo (due to the lap-band, everything has to be very small):

Because it came apart like this, tuna/mayo/gunk got everywhere, possibly even in the motor.  And because I wasn't thinking and didn't unplug it before trying to remove the blades,  the "up" blade chopped into my hand.

I hope this makes it more clear about what happened.