>>507693698 (OP)It's funnier
Saying NIGGER via text actually gets funnier the fewer letters you use to communicate it. N is the funniest, but in this context it needed to build on the initial "n word" to set up an escalation for the punch line, so he increased the number of letters to a modest 2.5 in the panel. This also makes it appear as though he was arrested so fast it was practically mid-word, as well as employing the medium, a comic panel with limited space, in an appropriate way to execute the joke. Reaching to the edge of acceptable word use is also a common staple of humor as people react to things which go outside of what is commonly accepted, but still want to feel like a line isn't being crossed in a serious way. Holding back and letting the imagination finish a thought can be much more powerful than spelling it out directly, which was also done with the time game and lack of further explanation beyond the visual in panel 4.
Study hard and maybe someday you can help make Australia funny again