SPOILER ALERT - if you haven't watched any of the show, the below may spoil some things for you. If you've seen season one, you'll be fine, proceed.

After finishing the recently dropped 2nd half of season 4 and reflecting on the show in its now entirety, something struck me that I'm not clear on.

Marty originally said no to taking on Del as a client. While not making a moral judgment about the who or why of the skimming, he simply observed that there were some irregularities that Del would do well to investigate, and it was that savant-like gift with numbers that made Marty special.

As we all know, Marty and Bruce would eventually say yes to Del, and start laundering for him.

Fast forward to the night Del showed up unannounced to accuse them of skimming. Bruce admits it was him and him alone, and "Marty didn't know."

And this where, on reflection, I'm lost.

Bruce was the blustery frat boy dude bro sales guy, Marty was the numbers guy.

A) How on earth did Bruce skim all that money and Marty not know about it?

B) How on earth did Del accept that Marty did not know? I mean, I know Del was seconds away from shooting Marty as well, but why would Marty's appeal to fix it even fly with Del? Fixing it required that Del trust Marty again after he should have proved he either wasn't that sharp or wasn't that trustworthy.

If Marty knew what Bruce was doing, he's complicit; if he didn't know, then he really wasn't as good as he was.

But the show proceeded on the basis that Bruce did it, Marty didn't know, meaning Marty might still be trustworthy, but he apparently wasn't that good, which is why Del would say, repeatedly, he was not sure Marty could do it. But then, why bother with Marty at all?