How does snakemake know files created though a slurm job are incomplete when job is canceled?

for example, if running a job that sumbits to slurm and canceling slurm job via

scancel -u username

ctrl-c

The files below seem to be incomplete. If you are sure that certain files are not incomplete, mark them as complete with

How does it know this? Does it make its own "touch file" internally?