Yes, it's inconsistent. If you select a single word it offers the choice to "highlight". If you select multiple words it doesn't just select, but automatically highlights and you have to undo the highlighting if you don't want it.
I didn't have as many accidental touch or swipe errors on my Sonys or on my Tolino. I guess the Kobo screen technology is more sensitive or something.
Also the Kobo is the only reader I have that occasionally when I swipe forward, it turns back. This doesn't happen in every book, but once it happens in a particular book it's likely to happen again in that book. I think the touchscreen just doesn't like me
These days I mostly use my Tolino if I'm reading in the daytime since I have fewer issues interacting with it. I use the Kobo to read in bed before going to sleep at night because it has the warm light.