(Mishnah): If one became Tamei in the Azarah, then forgot the Tum'ah but remembered (that he was in) the Mikdash; or, if he forgot the Mikdash, but remembered the Tum'ah, or he forgot both:

If he bowed (before leaving), or delayed the time needed to bow, or left on a long path, he is liable. If he left on a short path, he is exempt.

This is a Mitzvas Aseh (to leave on a short path) in the Mikdash for which [the Great Sanhedrin] are not liable [for a mistaken Hora'ah that that caused most of Yisrael to transgress an Isur Kares).

(Gemara - R. Chizkiyah citing R. Ami citing R. Lazar) Question: It says "Es Mishkan Hash-m Timei", and it says "Es Mikdash Hash-m Timei'!

Answer: This teaches that there is a distinction between one who became Tamei inside, and one who became Tamei outside. One who became Tamei inside [is not liable] until he delays the time needed to bow. One who became Tamei outside [is not liable] until he enters Rosho v'Rubo (his head or the majority of his body).

Question: If one became Tamei inside, and entered inside [the Heichal, or the Kodesh ha'Kodoshim, is he liable once he enters Rosho v'Rubo, or not until he delays the time needed to bow]?

Answer: We learn from [our Mishnah] "he bowed, or delayed the time needed to bow" (this is more than the time needed to enter Rosho v'Rubo). Since delaying [the time for Rosho v'Rubo] is not like entering Rosho v'Rubo, and you say that it is until he delays the time in order to bow, here it is until the time needed to bow.

Note: If one were liable for entering Rosho v'Rubo, he would be liable for delaying the time to do so, like we say about bowing.

Question: [If he went on a long path,] for what is he liable - for the first [distance that he walked], or for the latter [after walking the length of the shorter path]?

Answer #1 (Talmidim): It is for the latter.

Objection (and Answer #2 - R. Yosi): We tell him "leave" [and he is doing so now]. Can you say that he is liable for the latter?! Rather, it is for the first. (We explained this like RIDVAZ.)