Consultants I work with have to make very late adjustments to clinics, surgical lists etc due to, in no particular order and off the top of my head -
Illness
Child illness
Other caring responsibility (e.g. elderly parent crisis)
Nanny illness
Grandparent (back up childcare) illness
Teenage child crisis (mental health)
Delayed travel back from leave
Bike accident on way to work
Bereavement
Emergency dental issue
Delays on motorway on way to work
Broken bones (mountain biking)
In fact all the same things that other people experience in life. Short of expecting consultants not to have children, not to mix at parties/events to catch illnesses, not to go on holiday in case they get stuck, not to have any physical hobbies, not to be in relationship with other doctors, not to travel to work... Even the best laid plans of back ups fail.
It isn't proportionate to have multiple layers of expensive back ups just in case. As per my list above small child illness is an occasional factor and one factor among many. Doctors are not robots, they are human like the rest of us. And, all bar one that I have worked with over my career, they are extremely dedicated to their work.
But life happens and expecting otherwise is ridiculous. Doctors are bound by the same set of leave policies as the rest of us (sick, carers leave, special leave, bereavement leave, parental leave etc) so if some on here are angry about Doctors having occasionally to take time off in an emergency, take it up with the policy makers not the individuals. And calling Doctors out for being morally and ethically unsuitable for the job if they don't sacrifice themselves on the altar of their job at the expense of their life is insulting.