@d
Sins of commission are done by performing actions, while sins of omission are done by not performing actions when you know you should have.
In our investment business, this shows up in different ways, mostly in deal flow. Sins of comission include; assesing a company fully and deciding not to invest, to then see the company grow and become successful, these are common, and are easy to catch. Sins of omission are harder to catch and include; ot answering to DMs/emails on time, not going the extra mile with relationships that could have led to an amazing deal, it's not spending the extra hour on a deal and try to change your mind, it's seeking for confirmation bias by not looking for discomfirming evidence on a deal, it's not reference checking a company or founder.