In fact there is several scenarios
At first, don't forget that a job is executed by the Control-M Agent.
So if you Control-M server is down, your server having the Control-M agent is probably still running.
And because of that command launched too.
When you CTM Server will be back it will resynchronize information with the CTM Agent.
If job is finished, status will be change in CTM Server
If job is still running, status will be as Running mode (yellow)
If job is not started, CTM Server will submit on the CTM Agent the command.
But in that last case, you need to consider two things.
1 - I UNTIL parameter is not empty and earlier than CTM Server time back, the job will not start.
2 - If during CTM Server extinction, time of NDP (New Day Procedure) is due, job could disapear.