Did you even read the article fully, or my responses for that matter? The issue was not that she was attempting to overtly bully him via social media, her use of social media was simply evidence of her intent to drive the man to suicide while she pretended to be his friend and tried to elicit sympathy for herself. So IMO it is not appropriate to make a direct comparison to "cyberbullying", because this was not that situation. I do however agree that "cyberbullying" legislation, or laws against "trolling" are not able to be justly enforced, are moronic and shouldn't exist.
However, this is a unique and clear cut case of harassment with INTENT to cause harm to the man along with MOTIVE. In law intent and motive are very important factors in prosecution, and I believe the information gleaned from her social media activities and texts clearly show her intent and motive to cause harm to the boy via psychological manipulation and abuse in order to serve her own twisted purposes. There are plenty of laws on the books about harassment, stalking, and abuse of disabled (aka psychologically ill people) that could easily be invoked in this case without using "cyberbullying" legislation.
As far as the gender issue, I disagree. This is very clearly an issue of gender bias, at least in your personal interpretations if not on a national scale.
You brought up Amanda Todd, and this is a perfect example how a similar situation, when it happens to a female is almost universally considered to be a travesty and predictably people cry out for the perpetrators to be brought to justice. Given Amanda Todd was a minor, so I am not sure a direct comparison is appropriate because of this, but it does demonstrate how when such events are perpetrated on a female the reaction is to immediately seek reprisals. Then in the same vein when an even more purposeful attempt to drive someone to suicide for personal gain (rather than just mindless bullying with no real specific intent for result, or evident motive) is perpetrated by a female against a male, people such as your self are immediately dismissive and place the blame squarely upon the victim without a second thought. When a female commits suicide because of harassment there is a national outreach and push to find the perpetrators far more often then when a male is in a similar situation.
Some examples of how these cases are handled differently according to gender:
Females:
http://www.nytimes.com/2013/10/16/us/felony-charges-for-2-girls-in-suicide-of-bullied-12-year-old-rebecca-sedwick.html
http://cyberbullying.us/criminal-charges-filed-two-involved-rebecca-sedwick-suicide/
http://www.bbc.com/news/world-europe-27076991
http://www.theguardian.com/world/2010/mar/29/teenagers-charged-girls-suicide
http://www.cnn.com/2013/05/23/us/new-york-girl-death/
Males:
http://www.cnn.com/2013/09/02/us/connecticut-teen-suicide/
http://www.clickorlando.com/news/no-evidence-of-bullying-in-teens-suicide-investigators-say/31486066
http://www.huffingtonpost.com/2011/11/22/jamey-rodemeyer-suicide-n_n_1108458.html
http://www.startribune.com/local/271533511.html
http://www.lep.co.uk/news/local/family-call-for-ask-fm-to-be-shut-down-1-5629088
http://www.mirror.co.uk/news/uk-news/daniel-perry-suicide-teenage-blackmail-2172896
http://www.people.com/people/article/0,,20783199,00.html
General debate over whether bullying resulting in suicide is a crime: http://www.debate.org/opinions/should-bullies-be-charged-with-murder-if-their-victims-commit-suicide
As you can see almost none of the cases relating to male suicides result in criminal investigations let alone charges, while many if not most of the cases related to female suicides result in criminal investigations as well as criminal charges. I believe personal responsibility is important, and also that freedom of speech should be carefully protected, yet when there is clear intent with motive to convince some one to commit suicide there are plenty of laws that can be invoked and SHOULD be invoked in cases such as in the OP. Unfortunately even though the suicide rate for males is much higher, it is not often that investigations related to bullying are carried out when the victim is male. Why is no one asking why pushing a male suicide is some how less of a crime?