Sometimes, Slashdot posters who are under pressure to publish, anything, no matter what, to increase their publication count, will make stupid comments, mentioning terms they have vaguely heard about, without any real thought as to whether they apply.
P-hacking involves researcher degrees of freedom and the ability to find some signal for "something" in a bunch of data by varying how the the analysis is performed after the events themselves.
That does not seem a relevant at all in the context of this particular study, which uses a very simple method and measure for what it is testing and whose methodology was
pre-registered before it was done.