If you want to read a report about a runway excursion resulting from not stabilising at 40% on the NG there is a very good one on the CAANZ website where a PacBlue NG was asked to expedite while lining up at intersection Golf on 16R in Sydney. It drives home the importance of allowing the thrust to settle on the gauges, not just having the levers in the usual place.
If you are an examiner, give your next RTO scenario a freshen up by failing an engine at 20kts on the take- off roll, it is a great learning experience for the crew and will be talked about in the cruise thus spreading the message through the pilot group .
I like the fuselage drain theory below, sounds reasonable.