That's not much to do with Sanderson himself. Sure, he made all those typos while writing (who doesn't?), but a great deal of the problems with the book, including this one, are rather to blame on the rushed editing the book went through. Way too much to do, too little time to do it all. Team Jordan seems to have focussed its efforts mostly on avoiding continuity mistakes and fixing up individual episodes, and fairly little time on polishing up the book as a whole once Harriet assembled it all together and divided the chapters (which the book could have used, massively so). Why? Seemingly to stick to the deadlines.