@shadowfax: I'm sorry, I think I used the wrong words. by contradicting I mean to even ask "what if"s like "what if he punches from here?" or something like that.
@Brian: I think you have a good point about learning to transition to other technique. I'll give it some thought.. my sensei thinks of henkawaza as somekind of a specific technique that hasn't been taught by O Sensei. he may also have a good point in that O Sensei may not have an eternity to teach all possible moves for all possible situation.. his henkawaza IS based on basic tai no henko like tenkan, ikkyo undo, etc.. it's just that I'd thought that if he'd make up a henkawaza then he'll come up with something less sloppy variation.
I'm not learning martial arts ONLY for fighting reasons. as I said earlier, I actually like learning them. I know that aikido is not all about fighting, but according to a book I read, it IS still a martial arts developed by O Sensei by researching human anatomy and "perfecting" other martial arts.. so taking account that O Sensei was trained in fights and martial arts (a good one at that), I tend to think that calling a sloppy technique as aikido is a disgrace to His name and invention (Aikido).
@Graham: I think I have the same view on henkawaza that I think my sensei has. I think henkawaza is a variation of Aikido technique based on Aikido taisabaki.. but I think they still are not supposed to have many openings.
By your response to Brian I think you do need to give it some thought for I suspect you hadn't realized it's all about transition, change.
I asked the questions when and why so you could look at the purposes of doing such.
Firstly let me point out one major fact that hasn't been alluded to and which sort of fits with your 'complaint' or observation. Any technique you care to mention has more than one part to it. The first part of the technique done correctly will not only lead the opponent but will put you not only 'in control' but also safe from any counter. Therefore in truth the first part of any technique removes all danger.
Thus we come to the reason to change. Usually the most obvious reason is that there is more than one attacker. If after starting one motion, one technique, you become aware that you are putting yourself in danger with regards to another person who is trying to get you then you would naturally change what you are doing to align yourself with the second person.
So it's not in actual fact a matter of if you get stuck on one then you change to another as many think.
Knowing the purpose for doing it can then get you understanding and aligned in yourself and you can focus on doing it as such and thus just be aware of when another seems to be doing it incorrectly but not get stuck there complaining and wondering what it's all about.