It's possible he's using dicebot and the bot failed to connect for some reason and tried to unsuccessfully reconnect a few times, or he might have written his own bot or used another bot that runs on jdcapi (like tigers bot) that handles disconnects/reconnects incorrectly or tries to log into a whole bunch of accounts too quickly.
I just had another player complaining that the bot had lost all his balance, and that the same numbers were being rolled several times. Turns out the bot is showing the same bet multiple times:
Not sure what's going wrong, but it also seems to be skipping some bet sizes, and resetting on loss sometimes. Maybe it's user error, but it's odd how the same bet shows up multiple times.