Throwing an ender pearl in a nether portal has strange behaviors

I have also done this bug on 1.13-pre6. Both times this was done on a server in survival. Here is a video of me doing it: https://www.youtube.com/watch?v=uIjO-Un4SWY . It isn't consistent, but maybe that is just because i have blocks behind it and it works when i throw the pearl inside the stair hole. Also sometimes it doesnt teleport me to the nether coords in overworld, but just a few blocks behind the portal, like the pearl went through it. I couldn't replicate that in the video, but i have done this on stream: https://www.youtube.com/edit?ar=1&o=U&video_id=7yHhpIlVqac . I haven't also done that after the stream.