Yes it was fully saved. No the map file was not fully written to disk yet.
To improve application responsiveness and write performance modern OS will buffer writes to physical devices. This allows writing I/O calls to return near instantly for better application write performance and also for the physical device to be fed write commands efficiently for improved device performance. It also allows multiple small writes to me merged into single bigger writes potentially reducing the number of write commands required allowing the physical device to operate more efficiently. The caching nature also means that frequently rewriting data may generate fewer write commands and use less write bandwidth.
Of course the obvious problem is that if power fails between the time the application thinks the data has been written and the time the file buffer is written to the physical device then the file data will be lost and the file will become corrupt. When writing an application one can mitigate this to some extent by disabling buffered writes so that write calls only return when written to the physical device. However this mitigation is often ineffective since it may not factor in that physical devices themselves can have memory buffers to improve write performance and so prematurely signal the data as having been written.
The duration that the data is buffered is based on the amount of free system memory available, the amount of data being written and the write performance under the appropriate characteristics of the physical device. Saving a map file to a typical modern SSD with tons of free space might result in the buffer lasting only a second or so before it is written to non volatile storage. On the other hand saving a map file to a mechanical drive while writing out gigabytes of game files on a system with 16 GB or more of memory might result in the buffer time being several minutes in duration.
When a computer is shutdown, restarted or sent to sleep then by the time the power state changes all buffered writes will have been written out to non volatile storage. Additionally one can use a tool like RAMMap to explicitly purge the file cache contents and hence force all cached/buffered writes to be written out as soon as possible.
