I'd like to muddy the waters a little more on this one dwsiddall, as I've always looked on Obi-Wan as swiping twice in this scene!

We hear the lightsaber ignite, and immediately after we see the close-up of the blaster being raised by 'Freaky Nose', we see what looks like a short 1st swipe which would account for 'Freaky Nose's right arm being severed...which is followed by a 2nd swipe which I always look on as being directed at 'Walrus Guy' standing next to him. Obi-Wan's taking no chances here. (Have a look at the footage in slow motion or frame-by-frame to get a good look at what I mean) And both characters are seen to collapse to the floor, which convinces me more.

So I'm pleased that adywan has shown 'Freaky Nose's arm beside the blaster in his version, as although I think 'Walrus Guy's right arm/'flipper' was severed too, it doesn't matter...as it's landed offsceen a little from 'Freaky Nose's arm, and is unseen by us.