Yeh, that's what I thought initially. The section of the draft eligibility rules that seems most relevant is this:
"PLAYER NOT ATTENDING COLLEGE. Any player who does not attend college is
automatically eligible for selection in the next principal draft that is conducted after four NFL regular seasons have begun and ended following either his graduation from high
school or graduation of the class with which he entered high school, whichever is earlier. If
four football seasons have not elapsed, he is ineligible for selection, but may apply to the
Commissioner for Special Eligibility pursuant to the conditions in the section below entitled
?Special Eligibility.? If said player is not selected in the draft for which he is eligible, he is
eligible to be signed as a free agent, unless he subsequently attends college and participates in college football. In such event, he shall become subject to the rules that are applicable to players who attend college. "
https://www.nflregionalcombines.com/Docs/Eligibility%20rules.pdf
If the 'automatically eligible for selection' bit is taken literally (as some guys on the Reddit link on previous page believe is correct), then has actually gone through a draft without knowing it. It's pretty tricky though, and the rule was clearly written with US players in mind.
