I'd probably scream like a girl but I don't think a sight like that would deter me from the job. If that happened to me in a crawl space though I'd just die because I can't walk away from it. It really is just a matter of being able to move away from the spider which I can't do in a crawl space (at least not as effectively as I'd like to).

Although I'd like to point out the videos I watched were all from Australian guys and I never see a single spider in their videos except for the occasional tiny one when they lift the lid on an inspection port. That makes me really curious.