Not sure if this has been mentioned yet but personally, to me, if I don't feel a tint of fear, a little peak of fight or flight with each ascent I make, I walk away from the tree. Not having at least a .01% of fear each time you head up something means your ego has overtaken your primal respect of death to some degree. And those are the days accidents are likely to happen. 24 years in at this point, with 20 years climbing & not one work day has passed where I don't go through a mental checklist to compartmentalize those little hairs on the back of my neck telling me "hey dummy do this right or you could die". I don't have wood to knock on this second or I'd mention my safety record. Now how you take that daily tint of fear & process or compartmentalize it, seems to be wide open for discussion & ask 500 climbers & you'll get 501 answers on how that process goes. But if you don't see it before you start grunting up a trunk, you likely won't recognize it once you're aloft & then it can rear up on you & truly become dangerous. So far as the particular situation you were in with the company & the health/condition of the particular tree itself goes... if they didn't want you any more because you communicated to them a safety issue, or personal safety concern, even if it was majority just your inner stay alive mechanism, you don't want them as an employer. If you pulled it several times a week & were constantly having the fear issues, different story, but first day, one job, being let go? Nah, that's not good management of a tree service if you offer any other value in what you bring to the jobsite.