True John.
The the R.R.S simply states "causes damage or injury".
The Appeals Committee has used the strictest definition of this term to include ANY noticable effect from the contact.
This even includes a scratch in the gel coat.
In the rules there is no difference between a "tap" and a "collision".

The "damage" portion of the rule was added in the 2001-2004 rules because so many of the monohullers were "rubbing"
each other in order to prove rules infractions.
But when 10 ton boats "rub" the damage can be expensive.
So the ISAF decided to stop the contact entirely.

The "injury" portion of the rule was added in the 2005-2008 R.R.S.

A point to ponder.
If the two boats were racing each other and contact was made with damage,
the burdened boat can do their circle(s) and finish the race, but the R.O.W, boat is DSQ!!!
Since you usually cannot drop this type of DSQ, the R.O.W. boat is out of the trophies.
So a burdened boat can "tap" a R.O.W. boat and win the regatta.
Remember that next time you decide to bring a boat up