This is plain wrong. Lightening is not on chain except at entry and exit points. By nature this means that anything that happens between is less secure because it has not be settled publicly. Until something has been printed into the blockchain with enough proof of work behind it to be considered immutable, it is simply not in the same domain of security. Comparing these two states is a joke because one of these states is ignoring the very reason why bitcoin was invented (rapid public immutable settlement). Until that settlement has occurred, you must do the very thing that bitcoin was created to remove... trust third parties.