Hiya, I think that everyone has a different perspective on what time span is acceptable to leave your rabbit unattended for.
There are no right or wrong answers, just as long as you base your decisions on common sense.
My own view, having cared for many rabbits , is that if we are planning to be away for more than 4 hours, I get someone in to do a visual check of all the rabbits. From years of bunny care experience, I have learnt that rabbits go downhill so rapidly, and need urgent intervention if they should get gut statis for example.
My perspective may be different to someone with only a couple of rabbits in their care, we have 36 here, many of whom have special needs and are more prone to problems than normal.
I feel that bunnies do need at least two checks a day, every 12 hours in any circumstances.
What the individual decides to do is entirely up to them, but I would not leave rabbits unattended for very long, as I have found time and time again, that being on the spot to sort things out quickly really makes a difference should rabbits become ill.
I dont want to make any one feel guilty for not being able to do what I am able to do though, as long as you do your best, that is all anyone can expect of you.
Best wishes