AvalonEdit ILineTracker issue

I've got a tricky issue related to ILineTracker. Consider these three lines in a document:

"one<newline>

<newline>

three<newline>"

Placing the caret on the second line (which is empty), pressing backspace will trigger ILineTracker.BeforeLineRemoved with the correct line number: 2. But placing the caret in the same place and pressing Delete will trigger BeforeLineRemoved with line number 3.

Internally this seems to make sense, but as the interface is presented it's kind of weird to delete line 3 (with a range covering the text 'three', which isn't removed at all)

Any insights, anyone?