Sometimes browsers will begin to load a resource then suddenly stop because the web app resets to a different URL, or the user did some activity, or the page has some JS that does a "reload", or similar things. It seems like when I've seen it, usually it results in an "abort" network error rather than a RST.

However, here it looks like the browser is getting the RST rather than transmitting it. To figure out about RST behavior in the wild, BIG-IP has a neat ability to log all of the reasons about the RST. This feature is discussed here:

K13223: Configuring the BIG-IP system to log TCP RST packets

https://my.f5.com/manage/s/article/K13223