OBEs could be delusional. It might be true that nothing exists beyond that which can reliably be measured mechanically. I honestly have no way of knowing for sure. I've had experiences I think might have been OBE, but I don't know if that's the case. It's really not important to me to name them OBE or something else. They are what they are. Being right about it won't make me a better person, won't help me make a positive contribution in the world.
The question is, whether we are subject to our beliefs or whether our beliefs are subject to our will. To be practical, what good does it do a person to believe one thing over another? To believe something just to be right has the benefit of ego gratification, and ego development can be very helpful in seeking wealth, power or fame. On the other hand, the path of spirit -- believing that there is more to your existence than what can be evidentially proven to the mass collective -- has been shown by the likes of Ghandi to work well for those who seek to bring truth and compassion into the world.
Do "ego" and "spirit" exist in the scientific reductionist sense of being quantifiable phenomena? I have no freakin' clue! Maybe? Does it really matter? Like I said, I don't really care if I'm right; that's not the point for me.