John could not have made ANY kind of security trades over the internet nor on his smart phone. It has to go through either the NYSE or NASDAQ.
You may be able to place a trade WITH a brokerage firm over the internet but the brokerage firm has to make the final transaction, which takes place, over the wire and thoroughly documented, where the stock is listed…New York Stock Exchange, NASDAQ or OTC (over the counter). No one single person, repeat, NO ONE, can make any kind of trade without knowledge and complete and thorough documentation with the brokerage firm.
The trade has to be written by a licensed broker, approved by the brokerage manager, placed on the wire by the cashier, and confirmed when the trade was received. EVERY ONE of these people signing off on the transaction(s). If John stole all that money, all they have to do is trace the transactions that were made to see who made them. That stuff absolutely cannot be forged or doctored.
Once again they got it extremely wrong. I’ve spent enough years as a broker AND Securities Exchange Commission compliance officer to know this for a fact.