Is the punishment of the grave specific to the one who is ACTUALLY in a grave only?

Is the punishment of the grave specific to the one who is ACTUALLY in a grave only? 

Al-Imaam Ibnu Abil-Izz (Rahimahu Allah) said in his fantastic explanation on 'Aqeedahtu At-Tahaawiyyah' page 400 :

"And know that the punishment of the grave is the punishment of the Barzakh (Life of the Barrier), so everyone who dies and he is deserving of the punishment will receive his portion from it if was buried or not , if he was eaten by a beast or if he was burnt until he became ashes and was scattered into the air or if he was crucified or if he drowned in the sea, the punishment will still reach his spirit and body the same way it would reach the one who was buried."

Translated by: Younus bin Muhammad As-Somaalee

May Allah save us from the punishment of the grave.