Pretty sure this is a dichotomous thinking example?

Here is an example of what I think is dichotomous thinking/splitting:

Jane is walking down the high street and sees a friend she has not seen for a while and waves hello.
The friend, however, doesn't wave back and just continues walking.

Jane then automatically assumes that her friend no longer likes her anymore and that she must have done something terrible to upset her for her not to wave back.

As well as other cognitive thinking errors going on here I also think dichotomous thinking/splitting is at play here too. What are your thoughts?

I think there is a false dilemma<> here at play. It is an omission of choices kind of false dilemma in which other possible options are hidden or omitted. Another possibility other than that her friend does not like her anymore is that her friend might simply have not seen her.

I certainly don't see it as a fallacy or cognitive bias . It's simply just neurotic behavior. Haha!

You're right, it's an example of dichotomous thinking or splitting or black-and-white thinking.

In logic, we'd typically call this a "false dilemma" fallacy.

There are many reasons why her friend might not have waved, including but not limited to:

1. She might not have seen her

2. She might have been deep in thought (examples: her father was diagnosed with cancer and she just found out; she was thinking about her job interview; she was thinking about a relationship issue) and she might have physically seen her, but her brain didn't process it completely and she continued thinking deeply about the subject

3. She might have seen her and processed it, but she might have had something hard going through her life and so she didn't want to wave back and then for her to cross the street and talk. For example, she might have been diagnosed with cancer, she might be struggling in a relationship, she might be holding back tears because of something someone said to her a few moments ago, etc.

And there are also a world of far fetched, but still possible, reasons why. But, I'd lean towards the more likely possibilities.

Looks like a non sequitur...i.e. waving determines 'liking', not waving determines 'mad at'....etc. Waving or not doesn't reflect these dispositions always