The author shows that the formula given by B. Weesakul  for the absorption probability in a random walk between a reflecting and an absorbing barrier does not hold true in general. The correct formula in the general case is given.
"On a Random Walk Between a Reflecting and an Absorbing Barrier." Ann. Probab. 4 (4) 695 - 696, August, 1976. https://doi.org/10.1214/aop/1176996041