Akira's Pull in, ShRm Throw-

Hello reader,

Just wondering if someone can answer a question for me. I was watching a clip of Akira and saw something that interested me--he did f,b+P+G, P+K (ShRm), then did single palm followed by a double palm. The way it connected looked to me as if the opponent could not recover in time to defend the double palm (but, I am not an Akira expert). Is this true? Is the single and double palm guaranteed if executed fast enough?
Also, what else is guaranteed after the pull in, ShRm?
Any input is appreciated.
Thanks