It seems for me a bit contradictory with one of the OBE prerequisites: Having enough energy available.
How can OBE if we are extremely tired, unless we are enough proficient in energy raising at exit time, once reached trance status and therefore gained control over energy body..? Or not, I remember that RB at his Treatise on Astral Projection, Part 4 advices: You also need to feel you are very strong, full of energy and could climb like this all night.
This tell to us, we must to commit with an attitude leading to assured success. This only a think. I hope this be of help for you and overcome the conceptual puzzle related to "OBE while extremely tired" assertion. Sincerely, Natalia Parker