If you assign a task that is estimated at 2 days of work and it actually is going to take 2 weeks, it should be pretty clear way before that 2 weeks has elapsed. At that point you could get a second opinion from another employee in the same role as the assignee. That kind of difference in LOE vs actual development time should be rare. If it isn't, then your team needs to spend more time researching LOEs up front, getting solid requirements, and assigning tasks to someone that has the proper experience to complete the task on time.
I've worked as an engineer for a company that had ridiculous engineering turnover rates because engineers were treated like children, and management would always give these kind of excuses where one guy was a slacker one time so everyone has to abide by ridiculous policies around required office hours. If you want to retain talent and accurately measure employee performance, you need to put effort into measuring outcome rather than working hours.
I've worked as an engineer for a company that had ridiculous engineering turnover rates because engineers were treated like children, and management would always give these kind of excuses where one guy was a slacker one time so everyone has to abide by ridiculous policies around required office hours. If you want to retain talent and accurately measure employee performance, you need to put effort into measuring outcome rather than working hours.