We find that the probabilistic bound on delay in the article by Goyal et al. in 1997 is incorrect. The problem originates from: 1) the difference between stationary and Palm probabilities and 2) treating the arrival counting process over some random time intervals as if the time interval would be fixed. The error is propagated to some later work, e.g., recently by Bensaou et al., which derived some probabilistic delay bounds based on Goyal et al. in 1997. We give fixes to the above problem.