Yes a ball will pass between the top of the foot and the bottom of the bumper on the Cyclone II outside men. The gap is approx 1/16" but have never seen it actually come into play. The ball will not pass between the foot and wall on an outside man.
If it really concerns you you can always shave approx 1/16" off each bumper and that should eliminate the pass through. If you are blocking a bank shot odds are you will pull hard on the rod and compress the bumper enough to stop any ball from passing if it climbs the wall. The margin is so slim I doubt the weakness could ever be used repetitively - would not worry about it. Cyclone II is a good home table.
The table is a little on the light side - I used rubber mats on a concrete unfinished floor to stop the table from moving - works very well. Parts are easy to order as well as the table uses most of the standard tornado parts.