Well, there are different interpretations of "responsible and respectful." Personally, I think keeping up with current literature and consistently pumping out data while arriving on time almost everyday is pretty "responsible and respectful," especially in the research field.
Most PIs are more lenient on volunteering undergrads, since they're essentially just free labor. Honestly, 5-15 min. usually isn't a big deal, because what exactly does it mean to have that extra 5-15 min everyday? Read 5-15 min. worth of literature? Do 5-15 min. worth of experiments? Unless it's very time-sensitive it doesn't make much sense.
There are different interpretations, but which interpretation is correct is decided by the person in charge (which in this case is the PI).