As a general note, the example of the oil rig race brings up an important point. NOTHING said at a skippers meeting is official, unless it's in writing (in the NOR, SIs or a WRITTEN amendment).

There are some times when it is desirable to allow changes to be made verbally, but the procedure for this must also be, you guessed it, in writing. This is typically only used for small regattas (such as kids events). The procedure must be robust, however, and this should not be used lightly as it can easily be fodder for redress.

Yes, this is per RRS. There are also appeals cases that refer to this.

Mike