It does sounds like he has not adapted to being a father properly. He is still putting himself first. All trips have to be planned around the children when they can not fend for themselves.
Every trip with the kids is like a camping trip compared to my single days.
Never really got this attitude, we just tended to have a bag handy with all the usual travel stuff (nappies, wipes, spare cloths that sort of thing) and just picked that up on the way out. Could be up and out of the house in minutes with no real additional fuss. Friends of ours however made every trip out with their child an exercise in logistics.
As to the OP, not something I would do but then it all depends on the circumstances and if they were only going to be gone a few minutes then the risk is pretty minimal.