OK to have the bold piece of this sentence?

Hi, Andrew,

I wonder how laundering can be legal. You can only launder assets that are not precisely clean, so to speak.

@Andrew Van Wagner posted:

It’s important to understand that there are very fine lines—Donald has laundered money, but a lot of people have laundered money all over the United States and a lot of that laundering is actually legal.

Hi, Andrew—Gustavo has made a very interesting point related to the content, and that may make you want to revise the sentence as a whole. I'd just like to point out that you have neglected to use a comma before the bold piece of your sentence, which is the fourth sentence (independent clause) in your sentence:

• "It's important to understand that there are very fine lines."
• "Donald has laundered money."
• "A lot of people have laundered money all over the United States."
• "A lot of that laundering is actually legal."

Thanks so much! I greatly appreciate it!