volume bitmap error question

hello apple community

i was recently downloading a file to an external hdd (OS 10.12.6, hdd formatted mac os extended - journaled), and the hdd spontaneously improperly ejected during the download. this was the second time that that happened, so i dod some searching on the internet and found that it was suggested to run disc first aid within the disc utility app.

as the disc first aid scan was taking place, one of the messages was something about a volume bitmap error, and that a minor repair was needed (i kick myself for not taking a screenshot of the message for the exact wording. if that first aid log can be recovered please let me know).

in any case, the error seemed to be related to a discrepancy between the number of blocks shown as free vs. the number of blocks that were actually free, and the repair was successful.

i'm not an expert on how hdd's operate, so i tried to find out as much as i could about bitmap errors. there seem to be two kind of bitmap errors that would be related to an interrupted download (i.e.hdd improperly ejecting during the download):

1. the directory marks certain blocks a free, even thought they are not (orphaned blocks)
2. the directory marks certain blocks as not free, even though they are (phantom blocks)

i simply deleted the incompletely downloaded file, so if there are bitmap errors associated with just that file then it doesn't seem that i need to be concerned about it. but what i'm wondering is, does the orphaned/phantom block issue relate only to blocks associated with the incompletely downloaded file? i'm assuming that the bitmap error was generated because of the interrupted download.

i just want to make sure that i don't have to worry about previously fully/successfully downloaded files being affected.

thank you for any input on this!