"telling them" isn't always an option... I've been called pretty much every name under the sun and gotten harassing text messages for turning down a guy or two

I once had a guy friend (now an ex friend), who I had been friends with for close to almost a year and who knew I was into girls, suddenly blow up and try and hit me with a glass bottle because I wouldn't go out with him

my point is, you can never anticipate how someone will react if they get rejected, and people get scared and anxious because of past experiences even if it's completely irrational
personally I'd like to keep it 100% honest even with my history, but that's not a realistic course of action for everyone

I'm sorry it didn't work out between you two, and if she did indeed ignore you out of maliciousness, that's on her and she has to live with that