I'm not arguing one way or the other, but it's ours to say whether we regard it as one thing or three things. For example, would you want other indicators to appear between those three items?
And as it is, if they were the only things on the bar, would you want the whole bar highlighted? I wouldn't.
I'm a stickler for model purity, because it's the only thing that holds up in the long run. Currently, highlighting adjacent items with the same color makes them look visually joined. One might like that in this instance, but it wouldn't be desirable in a case where the indicators are totally unrelated. So, for better or worse, I think we should design the model to be pure, even if that means separation, which, afterall, isn't so bad. I'm passionate visual polish, but clear communication comes first.
Since the API does not provide a mechanism to group items, an indicator is either a singular item (and should look that way, I argue), or multiple indicators can be implemented in a single item, and will appear that way. So maybe all three are an "exposure" item that moves, highlights and shrinks as a unit. Or maybe they are three items that always look like three items. Letting three items look like one leads to artifacts, of which we've identified some so far: inadvertently 'joining' unrelated items and the end-spacing issue.