BizJetJock EASA comprises the following: the 28 EU member States all of which have full voting rights. The 3 European Economic Area (EEA) member States(Iceland, Norway and Liechtenstein) plus Switzerland. The latter 4 States have reduced voting rights but in all other respects are regular EASA members.
Despite your assertion, both the Commission and Dr North have consistently demonstrated that they "know what they are talking about". In this particular case, the point being made is that on "Hard Brexit" with no agreement, UK becomes a "Third Country" (an EU legal term) and thus, by default, a non-EASA member as membership is only open to EU and EEA member States plus Switzerland which has a special deal and which, according to the Commission, will never be repeated.
The solution to the problem is either stay in the EU or leave EU but retain EEA/Single Market membership (we are current EEA members under the EU banner) by rejoining EFTA (European Free Trade Association - UK was a founder member but we left to join the EEC) and thus join Iceland, Norway, Liechtenstein and Switzerland under the EFTA banner (Switzerland is EFTA but not EEA - confused yet?).
Incidentally, going the EFTA/EEA route following Brexit will not only take us out of EU but keep us in the EEA/Single Market and also solve the Northern Ireland/Republic of Ireland border conundrum. As they say, "what's not to like?".