I know that often video doesn't "show" what is happening, but watching this a few times, while the technique is being done crisply and cleanly, I don't see uke being off-balance - either laterally weighted onto one foot or uprooted onto tiptoe - before Kanai Sensei moves under her arm.
I don't consider it safe for me as nage to proceed if my opening hasn't unbalanced uke.
I may be off-base here but that's my honest interpretation of what I'm seeing.
I'm not sure it is right place to discuss about Kanai sensei detailed teaching. My intention was to provide an example of powerful throwing from shihonage as requested by Tim. As one can see it quite possible to throw from shihonage with a lot of power an still uke can receive technique in safe way.
Yes we throw this way outside, in order to i.e. maitain correct nage posture - throwing inside compromises martial principles. Also, unbalncing is done by maintaining strong lock on attacker arm elbow from the moment of the contact all time down + keeping him always in mouvent.
This strong lock serves as a connection to uke center so in the moment of throwing it is enough that nage moves his center across a center of uke and throw happens without doing any waving with the arms.