Awkward ambiguity

From David Morris:

The Sydney Morning Herald website  is currently showing a headline –  "How to not accidentally harass someone at the office party".

(So, how to deliberately harass someone …?)

There are lots of possible parses — the one that bothers David is

[How [to [[not accidentally] [sexually harrass someone at the office party]]]]

…or any of the other possibilities where not is tightly bound to accidentally.