Do-overs are only allowed during the SEC tournament in NCAA Women's play.
I have to agree with MTD on this one.
4.1 on the clock, ball OOB near the division line.
Don't negate a completed throw-in. That was action which took place and has to count.
Since you don't know exactly how much time to take off the clock, don't take off any. Tell the coaches that the timer made a mistake and that's the way it goes.
Hopefully, the NFHS will adopt the .3 minimum rule.