IMHO, its relatively easy to get even trained people (except at rather high levels) to over extend.
So yes, I tend not to throw them but let them fall because of their own body momentum, mechanics, and alignment. Also because either their mind really wants to hit me or their mind really doesn't want to be hit by me.
I've done lots of styles, outside of aikido, and one thing is a real fact. It is very hard to get people to over extend who have had training, boxers rarely do so, they throw punches from a balanced point. Watch a judo match, all that stand up grabbing and scruffing is required because neither is willing to extend, they are pulling all their energy inwards to maintain balance. In BJJ it is a mortal sin to over extend, do that I'll take your back and choke you out in seconds.
Yes trained people do over extend, in Aikido, because it is about flow, energy and it is dynamic - which is what I love about the art.
My take on these things, is and always will be, that it is all legitimate for the Art that we(you) do but so many people make the mistake of translating what works in the aikido Dojo to outside of it.
That is my point in this whole discussion. We must recognise what works in the Dojo and what doesn't. So many Aikido instructors just don't get it, instructors have a responsibility to their students to understand this deeply. But to do so sometimes requires a level of self understanding, and at times eating large amounts of humble pie that most will not consider, or do this.
And so the myths are continued to the next generation...