Short volume is something that is required to be tracked by law and disclosed, so by saying "from what you can tell there's no shorting", you're actually saying "I didn't bother to check"
Short volume has been upwards of 50% on some days where there is low volume and few buyers, but it's typically btw 30-50% -- check SEC docs. So on a day like today, where there are few buyers, short volume is likely pretty darn high.