I have had a few bikes over the years that did that. If your not using enough force there is a neutral in between each gear. I'll shift into neutral from first once in a while too, so I'm prone to do that and have had a few ghost shifts on my 2013 in the last 2k miles. One jumped back into 4th with no bad sounding clunk. But once it jumped out of 5th and right back in with a clunk. That one was concerning but no trouble since. I don't speed shift. It will haul ass with out doing that. Have never heard of anyone nor have I had a bad shift with a heel toe shifter.