Banks clear transactions overnight, in batch. Having it happen from 1-4 AM is normal, with modern technology it's reasonable that it might show up instantly once the batch physically clears (as a database transaction). The question is when it shows up in your account as "available"; sometimes that means "recorded on your account", sometimes it means "available to transfer out". It's also possible that funds which were deposited on Aug 18th by Greer's employer were recorded, but not available for transfer until the nightly batch cleared.
So I'll rate it as possible that Russ is telling the truth; the pay transfer hit his account on Monday, but wasn't available for transfer out until the nightly clearing. That would require him to know these timings ahead of time, spending the night hitting refresh on his account until it let him transfer. But if he's been desperate for immediate cash before, it's possible he's familiar with the timings. He does plan to do everything at the last minute, as we know.
Of course it's more likely he was trying to come up with a last minute motion and failed, so he gave up and transferred late out of spite.