"the price of gold may remain high, but investment demand for silver may disappear at that point in time and that may cause the price of silver implode."

If any implosion is to happen it will be the opposite. Gold is an investing commodity (money) subject to public opinion as to it's value so if any implosion is to happen gold is the better candidate of the two.

Silver on the other hand while being similar to gold is also an industrial commodity that is continually being used up. Think about that for a few seconds.
Silver is being dispersed into the environment and for most practical purposes, not recoverable. For the price to drop, demand must for all practical purposes disappear. That means industry must stop operating.

I suggest that, unlike gold, it needs to be continually replenished. That automatically implies that there is a continuous demand for silver, so how can it implode? Only to a very temporary degree through severe manipulation. However after that it's price would have to even more severely explode to compensate for the manipulation.

If anything he is trying to deflate the potential of silver by implying the opposite.