What if he sneezed on the plane? Wouldn’t that be spreading it? What if he had a runny nose and left a tissue in the plane pocket? Oh, I can think of a whole lot of ways he could have spread it.
Could you catch it by touching the same door knob?
It he were shedding virus at that point, possibly yes, to those fairly close to him (~5 rows).
But this is not an airborne virus that would waft on air currents up and around the entire cabin and through the ventilation system.
What if he had a runny nose and left a tissue in the plane pocket?
Yes, if virus-laden this would, of course, be a real hazard to the clean-up crew. Although they usually wear gloves, a real chance of infection when they removed the gloves or touched a glove to their face.
Pretty sure I read Ebola strain can survive 24 hours + on hard surfaces so very easy to transmit from an infected person... doorknobs, ATM buttons, shopping carts, fast food...