Hi, sorry for the late reply, I've been extremely busy with work for the last couple of weeks. Yes, the structure he describes is exactly how the block lattice operates. Each transaction consists of two pieces, one withdraw transaction and one deposit transactions, and each of these occurs on their respective blockchains so as such there is only one transaction type (deposit or withdraw) per account.

This ties is very closely with tried and tested methods of duel entry accounting (always have a debit and credit in a transaction and neither of these can be in the same ledger). This is one of the most likely ways of achieving a true asynchronous, highly scalable blockchain.

There is a tremendous use potential for this in various fields, I'm currently exploring and working on some that are completely non-crypto related.