I don't know where your teacher was taught, but if he trained at Hombu dojo (Aikikai Japan) he would have been instructed by many different sensei, as each sensei teaches on different days and different times -- you get a good exposure to many sensei. If he trained in a different dojo in Japan or one in Indonesia, then he may have had only one or two main sensei, but was exposed to certain techniques when other shihan visited (or via video tapes, books, etc.).
My sensei were all trained in Hombu dojo (Aikikai Japan), so they all received training from many top Japanese sensei -- and always let us know when a particular technique or variation is from a specific sensei (that is usually the way in Budo, one makes reference to the teacher who taught you the technique so as to pay a small homage to your teacher).
Who knows, maybe your teacher spent more time with Watenabe (or one of his pupils) and gleaned more "secrets" from him (such as this "freezing"). The longer one spends with a teacher, the more secrets they reveal (although sometimes you have to "steal" certain secrets from them as they will never teach them to you directly -- you must notice them).
While Ki is an important element of all Aikido, Koichi Tohei (shin-shin toitsu Aikido, or Ki Society) has been the main proponent of "magical and mysterious" Ki development in Aikido. Perhaps your teacher has trained with shihan from that style?
Incidentally zenpo (or forward) is a term almost exclusively used in shin-shin toitsu Aikido (Tohei's Ki Society), and most other styles (Aikikai, Yoshinkan, Tomiki, etc.) do not have that term so I don't know which technique it corresponds too (perhaps irimi-nage or sumi-otoshi…Mr.Profitt?).
Jiyu-waza, however is a common term in most Aikido styles used to denote "free practice", or unrehearsed techniques as opposed to the normal partner training you do where you take turns being nage and uke (kata).
Bruce
(Just Bruce, not Mr.Bruce please, -- you'll make me feel old if you call me Mr.
)