Promotion through paralysis

[Doniel Levy]

Bamidbor 25:1-4 seems to imply the Midyon sin took a while. Textually, it is nothing like the immature image I had of thousands of women invading the Israelite camp in the morning, by midday thousands had succumbed (24,000) and at lunchtime Zimri was outside the Ohel Mo'ed challenging Moshe. Pinchos killed him shortly thereafter and it was all over by tea-time. Apparently not. 

וַיֵּשֶׁב יִשְׂרָאֵל בַּשִּׁטִּים וַיָּחֶל הָעָם לִזְנוֹת אֶל בְּנוֹת מוֹאָב: - it all seemed to happen over a certain (long) period of time.

Which begs the question: where was Moshe, where were the leaders, (not to mention the wives of the 24,000 men)?

Rashi seems to address this question in Possuk ו

ו. וְהִנֵּה אִישׁ מִבְּנֵי יִשְׂרָאֵל בָּא וַיַּקְרֵב אֶל אֶחָיו אֶת הַמִּדְיָנִית לְעֵינֵי משֶׁה וּלְעֵינֵי כָּל עֲדַת בְּנֵי יִשְׂרָאֵל וְהֵמָּה בֹכִים פֶּתַח אֹהֶל מוֹעֵד:

והמה בוכים: נתעלמה ממנו הלכה כל הבועל ארמית קנאים פוגעים בו געו כלם בבכיה. בעגל עמד משה כנגש ששים רבוא, שנאמר (שמות לב כ) ויטחן עד אשר דק וגו' וכאן רפו ידיו, אלא כדי שיבא פינחס ויטול את הראוי לו:

Translation from Chabad.org 

while they were weeping: The law [that anyone cohabiting with a non-Jewish woman is to be executed by zealots] eluded him. [Therefore,] they all burst out weeping. At the incident of the golden calf Moses [successfully] confronted six hundred thousand as it says, “He ground it until it was powder…” (Exod. 32:20), yet here he appeared so helpless? However, [this happened] so that Phinehas should come and take what was due to him. — [Mid. Tanchuma Balak 20]

From what I understand, Rashi asserts (from Midrash Tanchuma) that Moshe was paralysed with inaction so that Pinchos could 'shine'. Pinchos somehow needed to "save the day". Can anyone explain? 

Is Rashi suggesting that Moshe did nothing (or was prevented by H from acting?) so that Pinchos could get a reward?