I have attached screenshots showing it teleports to the exact coordinates of the nether portal (in the nether) in the overworld instead. Also aiming the way I do in the screenshot semi-reliably reproduces this glitch.
Gurkis, I have tested it as well, if you throw it in the corner so it hits (or nearly hits?) the obsidian from an angle and slightly below the portal it will teleport you quite reliably if you aim it right.
I have attached screenshots showing it teleports to the exact coordinates of the nether portal (in the nether) in the overworld instead. Also aiming the way I do in the screenshot semi-reliably reproduces this glitch.