More on Ulla's opinion (based on Resh Lakish) that partial entry is akin to a complete entry - when it comes to an impure person and the Temple. In the context of "semihah" - laying hands on the animal - needing to be done in the same place as the slaughtering of the animal, usually without interruption (though of course our case is an exception). Note the distance between the gate of Nikanor and its relevance for the person with tzara'at. And note the effort involved for this laying on off hands - beyond just reaching out one's hand and touching the animal. Also, the impure person who handles the sacrificial, consecrated food - will he get lashes or not? (that's the ongoing machloket between Resh Lakish and R. Yochanan)