This issue comes up a lot. As a sibling comment says, if it is so common an occurrence for the character limit to lead to misleading headlines because they were overly condensed, you may want to consider slightly expanding the headline length limit (perhaps to 120-140). But I appreciate that it's a balancing act, because making it too long dilutes the punchiness of the HN front page itself. No easy answer here.
It comes up somewhat regularly but it's quite rare for there to be a case where there isn't a natural solution. For example in this case the HTML doc title not only fit the limit nicely, but was more neutral and thus better for HN. I think HN benefits from this limit.
