Earlier quoted context omitted.
It probably is over 100%. That’s unusually high but 100% short interest is not some sort of special number. Shorting works by borrowing a share and selling it to someone else. There’s no reason the same share could not be borrowed multiple times, as the shares are all fungible.
So if two people owned one share, they could simply pass it between each other until their shorts are covered?
A lends to B who sells to C who lends to D who sells to E who lends to F who sells to G.
The reverse of the process will unwind it:
G sells to F who returns to E who sells to D who returns to C who sells to B who returns to A