Whenever I paced for a race, I knew clearly what was expected. Also, they would give me any split I wanted to make sure I was comfortable. Almost every track had a clock at the 200 and finish line. I would occasionally ask for a 100 meter split just to be sure. Any adjustment could be made gradually from there to the 400 and then I was on my way. In my experience, 800 meter runners made the worst rabbits. They really had no concept of pace at all. I shared on another post that one time the pacer was supposed to go 2:10, which she did. Problem was, she ran the first lap in 60 and the 2nd in 70. She couldn't understand why everyone was upset. She didn't get paid, and I never saw her rabbit again.
While I believe the rabbit totally flopped, everyone knew it by the time they saw where they were at 200 meters. Plus I'm sure they could feel it. At that point they have to decide if they want to sacrifice themselves and do the work for everyone, or go for the win and know the time won't be fast. Going for the win is the smarter plan. There will be other chances to run fast, hopefully.
Rabbits sometimes screw up, and you have to deal with it. This one was particularly bad. Ah, for the days of Mary on the starting line. You knew exactly what was going to happen!