I believe actions speak louder than words.

Your application of that truism in this context is misleading. It is entirely possible for Bindel to be a bisexual woman who mistakenly claims herself to be lesbian. A bisexual person who chooses to only date one sex is still bisexual; that doesn't erase their bisexuality.

Furthermore, as jay-day already pointed out, she emphasizes that she believes that she chose to date women and doesn't believe in homosexuality. Who else can "choose" which sex to date but a bisexual?

Also she defines "political lesbian" differently than most people do.

She defines it exactly in the way that is typical of the homophobic radical feminist "political lesbian" concept... She says:

It ["political lesbianism"] is acknowledging the reality of compulsory heterosexuality, and being proud to reject heterosexuality in favour of lesbianism

She believes that homosexuality is a choice (and a lifestyle, as I already noted in my post). "Compulsory heterosexuality" is the idea that straight women are pressured to be straight because of societal influences and can choose otherwise if they'd like. I'm literally parroting her own words back; not sure how else I could explain it to you.