This isn't going to sound like a real answer, but I honestly wouldn't worry about it too much.
The Bionicle comics (especially the early ones) were very prone to errors. These were anything from coloring errors to penciling errors, and even speech bubble errors where the bubbles would be drawn to the wrong speaker.
So considering that fact, it's very likely the artist just drew Nokama holding the wrong Krana-Kal. I wouldn't put it past the comics to do that.
Here are some of my "favorite" Bionicle comic errors, by the way:
Lewa likes to talk to himself.
The Toa Metru don't have chest armor, apparently.
Nuhrii took a lucky guess and Vakama is amazed.
The first two years of the Ignition trilogy are the worst.
These creepy Matoran.
Vakama is made of rubber.
Nuparu suddenly gained some awkward chest armor.
I swear the artist just got tired of drawing Bionicle parts.
Voya-Nui suddenly looks like that.
This one's the worst. Perfectly drawn mask, scribbles for arms.
And for those who say this was just the 06-07 Bionicle comic style, then why are these so detailed and set-accurate?
I'm telling ya, it's because they wanted these panels only to look cool and the rest they got lazy with.
And finally, my favorite error:
Hewkii nearly destroyed Metru-Nui with his fire Nova blast.