I'm not sure of Phloston's experience applying to neurosurgery but it is something that will definitely be an area of concern for residency programs if it shows up as a remediation or fail. I think only your school's academic affairs office or the equivalent will be able to answer how that situation shows up on the transcript. There will definitely be programs asking about why that happened. The rules and advice that often are generalized for residency applications often don't apply to neurosurgery. Programs are extremely risk adverse due to the small size of the field and length of residency training, so it is a much more bleak situation than Phloston is painting BUT not impossible. Just remember, it is one of many data points that will be used to review your application for consideration.
Having said that, there are plenty of programs that don't even interview all solid or even stellar applicants, so if you have a little kink in your armor that is your application you're going to have to compensate in some way. I think in your situation, doing well the rest of the way (if there is an Honors grade, get it), doing well on Step 1 (240+), outstanding performances on your subis, and getting stellar letters of recommendations, and meaningful research activity will help out. Your letters and where you did your subis will always be a topic of discussion at interviews for all applicants. No one can give you a for sure answer that you will be ok or conversely that you won't get any interview since there are so many other variables at play. Ask your home department or any of your neurosurgery mentors about your chances as well since their support of your application will be extremely key with regards to helping you match. They are invaluable since they can use their connections to make phone calls and help you get interviews etc. Utilize all the resources you can since it is a tough process and there are plenty of socially normal applicants well-prepared for the match that have done everything right going on 15+ interviews that end up not matching.
I don't want to deter you at all but just keep in mind you absolutely need neurosurgery-specific advice and start getting involved with your home department if you haven't already. In general take all the advice you get with a grain of salt (even from neurosurgeons since their experiences and perspectives may differ from each other's) and ask as many people as you can for advice so that you yourself can make the most informed decisions. All applicants need to be extremely well prepared for the application process especially if there is a little red flag in the app.
