Oh, I see what he's saying. If you take too long, the other person will either get confused and tune out or think they understand the gist of it and jump to conclusions. People try to read the meaning under the words, which is what you're concerned about, so don't use enough words to give him a running chance at preemptive analysis. Use just enough to get the idea across, then switch to explaining and reassuring.
Helpful? No?