By the time of the Shaolin meet, DY's inner energy was already very much advanced and not shy of Xiao Feng's.
In all of JY's novels, when we see a person with lower inner force hit a person with higher inner force, the damage is often minimised if not virtually ineffective.
Now, I don't think anybody would argue that MRF's inner strength was _that_ great. MRF probably had even lower strength compared to DCQ, which is already a 2nd or 3rd tier fighter. DY's inner strength was already at 1st tier by that time.
And we know that Bei Ming Shen Gong has an 'auto-protect' function.
So when MRF had his foot on DY's chest, how come it was stated explicitly that he could _easily_ end DY's life right there and then if he just pushed down. It was written as if he didn't need to gather all his force or use a deadly technique but just step down with his foot.
Could JY have gotten a bit inconsistent as usual for the sake of plot?