When I was a younger developer, I did an interview for a contractor and while the candidate was okay, I wasn't convinced (basically he hadn't shown any reason NOT to hire him, but he hadn't put himself in the MUST HIRE category). In follow-up I told the person I was worried by their lack of experience but would move forward with an offer, but I wanted to let them know in advance that I'd quickly move to let them go if it wasn't working.
In my mind this was a great solution: we got to make the hire, he had a chance to prove himself, and we'd not get stuck with a bad match if he had flaws. By letting him know in advance I was ethically clear because he would enter into the situation with his eyes open. He turned it down and my boss was furious with me for saying all that.
Now, some 15 years later, I realize how terrible my view was and how many bullets I blindly dodged. My best managers have all bent over backwards to make a problematic hire work out. Seeing that has always served as a soothing presence on my own occasional anxiety. And in the many interviews I've conducted, people that fall in the "I don't see why NOT to hire them" have outnumbered the "We should totally hire them" about 4:1. Frankly, the interview process is inadequate to give you a good impression of working with someone and their strengths/weaknesses. Heck, I routinely discover new surprises about co-workers after working with them for years.
My past self had been pining for an easy way to fire someone in order to dodge responsibility for the hiring decision. Now I see the hiring decision as not "are they great?" but instead "will I be able to work something out if they aren't great?" because we can't dodge the responsibility nor can we actually reliably be correct in our evaluations.
Unfortunately, my current view doesn't seem to match current hiring practices, where they want everyone to hit the ground running and magically resolve problems that are generally caused by non-technical issues (low staffing, contradictory customer pressures, etc).