How do I protect myself?

I am an undergraduate and I have applied for a position on a committee X where X has both a student and professors. P is a member of the committee and also happens to be in an advisory role for students in that department.P is also conducting the process for filling up the position.

There were no candidates for the position and I am the only one. A notice was circulated to everyone in the department addressing everyone in it(students only) to unanimously endorse my candidature within a one-day deadline.

1. As the deadline was about to be over with a few people remaining (they were held up by other things like examinations), I approached P to extend the deadline but shockingly P responded by asking(shouting at) me why I was so anxious about it. P accused me of being used to getting benefits from the department and P also stated that the notice was for everyone but me as I could not possibly oppose my own application.

P also stopped short of suggesting someone else was behind my anxiety to fill in that role.

2. I had approached P so that it might not look that being a candidate for the post, I was least interested in it and hence the follow-up. But that seemed to have backfired.

From the outburst, I concluded P was in a bad mood and hence the outburst but I am not sure. Is there a way to protect myself from these kind of events, in particular during my term in this post?

I have absolutely nothing against P though P has a prickly reputation(and he was quick to emphasize that in the outburst and asked me to be mindful of it) and I would like to be at least not hated by P.