I totally get what you're saying, doing the right thing hurts and isn't easy to do. However I grew up being nailed against the wall more than once for something I didn't do, and it's a terrible feeling. The idea of destroying a person's career over an allegation is not okay to me, because it's too much power for one person to have with basically zero proof (To my knowledge).
Lastly the only thing I disagree with you about is that the party is priority. That is basically Hollywood style writing, the party does not come first; most of the time the 'party' is being reborn. It's character weakness to capitulate in this situation, the party has no tangible worth, only the individual does.
What are we going to do once the dust settles and we've properly factored that we've sabotaged ourselves of a leader?
In politics, the Party is more important than the individual. Absolutely. Leaders come and go. The Party remains. I've worked within two. That's how it works. Any leader who believes they are worth more than their Party is either leading a cult of personality (thus not a party) or has failed to understand that their ego is drastically over-inflated.
I cannot over-emphasize that politics is a different animal than any career. Politicians know this. They get the positions they do based on political considerations and lose it often based on the same. Lies do in politicians all the time. So do truths. So do uncertainties. People vote for and against politicians for reasons varying from the good to the very bad. It's not fair, but politics aren't fair. Should politicians lose positions based upon allegations? Absolutely. They can also muster sufficient political power to keep their positions despite allegations -> look at Trump.
Can bad results come from this sort of thing? Absolutely. In politics, that happens often.
I often say with Brown that I have made the decision to suffer his resignation if it was wrong to do because I am not willing to wait to see if they are found true when he's Premier.
I have other posts to write on this, including one as to why "innocent until proven guilty" isn't likely reliable here and is not the accepted standard in politics anyway.
You risk something great to what you care about. You see, people like me are entering into politics. My primary mission is to disrupt the status-quo, and good luck getting me to step down should you decide to throw an allegation towards me, because I'm no politician. I'll be the PM of Canada and regularly flipping people off. I'll tell the speaker of the house to go fuck himself if it suits me, it wont matter because real people will support me as their leader.
I love how right now NDP leader used the word "bullshit" and people want him to step down. Sorry but I want a measurement of efficacy in office, not political capitulation.
You should think about that, what you risk pushing people out like Brown. Eventually all that you're left with is radically progressive technologically proficient and articulate debaters. Entire parties will be destroyed by people like me, people who never wanted to go into office but feel compelled through a real sense of duty to progress the country forward.
I don't agree with Trump always, but I love that he says whatever he wants. Last thing America needs is a politician as president.