Comments on: ?erasure rate analysis and tighter upper bound for binary product codes?

The above paper, by AH A. Al-Shaikhi and Jacek Ilow, claimed to have developed a tighter upper bound on post- decoding erasure rate for binary product codes by deriving the exact number of unrecoverable erasure patterns over some range of the number of erasures. We show that (Equations 9 -12) are inaccurate, and hence the resultant tighter upper bound is questionable.