The TC is not a count is it? It's a product calculated from the RC, used simply to determine the increased number of high/low cards left in the shoe, averaged per deck. From that info we make assumptions and bet accordingly.
The cut card in the shoe will mean that it's rarely going to be the case that the RC is zero when it pops out as it's rare that all of the additional high/low cards have been distributed in front of the cut card and played out.
If when the cut card comes out the RC is still high (I've personally seen it at +10), then it means you've been assuming an advantage, and betting on this assumption, when in actual fact it was never there - the additional high cards would never have come into play.
What was the original point of discussion?