Ooh, just a little bit dangerous

When I arrived at the pool tonight to swim, all the lanes were filled. So I determined that I would need to share a lane, and set about identifying which of the several single-swimmer lanes to ask.

After scoping things out (in all my near-sighted wonderness) I went up to a gentleman as he stopped on the wall, and the following conversation ensured....

• Me: "Is it alright if I share the lane with you?"
  
  
• Swimmer in water (SIW): Yes.
  
  
• Me: Cool. Do you want to split the lane or circle or something else?
  
  
• SIW: Well, actually, I'm doing backstroke right now, and I won't really know where I will be.
  
  
• Me: Oh, ok. Well, so do you want to pick a side and-
• SIW: I don't know where I'll be; I kinda go all over the place when doing backstroke.
  
  
• Me: That's alright: I can keep an eye out for you. So should I take this side-
• SIW: I kinda go all over the place, and can't really stay straight.
  
  
• Me: It should be ok, should I just take-
• SIW: I just don't really stay on any one side.
  
  
• Swimmer in the neighboring lane: You can get in here.

Now, as his responses progressed, I began to wonder why the gentleman initially said that it was ok for me to share the lane: with each subsequent answer if became further apparent that it was not alright.

Get out of my way, get out of my sight
I won't be walking on thin ice to get through the night