Low-complexity error concealment techniques for mobile applications are studied extensively in this paper. The boundary matching algorithm (BMA) is an attractive choice for mobile video concealment due to its low complexity. Here, we examine a variant of BMA called the outer boundary matching algorithm (OBMA). Although BMA and OBMA are similar in their design principle, it is empirically observed that OBMA outperforms BMA by a significant margin (typically, 0.5 dB or higher) while maintaining the same level of complexity. In this work, we attempt to explain the superior performance of OBMA, and conclude that OBMA provides an excellent tradeoff between the complexity and the quality of concealed video for a wide range of test video sequences and error conditions.