I don't think that's a reasonable conclusion to draw from the fact the TV wasn't pure noise. Why would the agent not be able to determine that every noisy frame was one step away from every other?
But how do we decide whether the agent is seeing the same thing as an existing memory? Checking for an exact match could be meaningless: in a realistic environment, the agent rarely sees exactly the same thing twice. For example, even if the agent returned to exactly the same room, it would still see this room under a different angle compared to its memories.
Instead of checking for an exact match in memory, we use a deep neural network that is trained to measure how similar two experiences are.
If there is an unlimited number of shows and the agent walks right up to it, I think its still trapped.