I agree with you, but was trying to illustrate an example from the class of 'one byte is eight bits' style assumptions.

Hopefully I made it clear that 'one character -> one byte -> eight bits' is an assumption that can cause a lot of pain. The simplest usage of non-standard character bytes I can think of from the top of my head is in SMS (as described in that interesting article that was submitted these last few weeks sometime) where the standard used 7-bit character bytes in order to get longer messages, and then struggled to deal with international character encodings.

Maybe it's drawing a long bow, but I think this specific example is of the same class of assumptions that jacquesm was describing when they said "a byte is 8 bits", and clearly this is a problem that will not "only cause trouble in rare cases".