I am sure your CF card is fine. Old 68k SFS has a bug where it trashes its journaling system when writing to multiple files simulatenously. It is extremely rare but it does happen. Luckily you dont lose any data but just have unwritable partition and certainly it is less hassle than FFS.
It has happened to me on my A1200, and it happened to me on my Pegasos until SFS was fixed.