Jess, I'm definitely no expert on bottles, but I think the main problems they are worried about are the ear thing and teeth decay. But those are both mainly a problem if the bottle is taken to bed and sucked on laying down or in their sleep (same applies to bf'ing too), or if they are walking around with a bottle for most of the day, especially if there is something like juice in it, instead of milk.

I think it's one of those things they try and discourage altogether, to avoid those problems. But personally i think if your ds has the bottle sitting up, finishes it then it's over, iykwim, then it really isn't a problem.

And all that is just my personal opinion, don't take it as gospel