One of the most interesting moments in Donald Trump’s news conference Wednesday came when Trump wasn’t even on the podium: Sheri Dillon, one of Trump’s lawyers, spent several minutes explaining why Trump couldn’t realistically put his assets in a blind trust, as many ethics watchdogs have demanded.

Dillon’s argument was complex, and she may very well be right. But that doesn’t mean concerns about Trump’s conflicts of interest are invalid.

The words “blind trust” have been thrown around a lot in recent weeks, but it’s worth explaining what that phrase really means. True blind trusts aim to shield politicians or other public figures from conflicts of interest (real or perceived) by ensuring that they have no control over their assets, or even know what those assets are.

A typical case works like this: Hypothetical Sen. Jane Johnson owns $2 million in stock in the tech company where she used to be an executive and an additional $3 million in stocks, bonds and other investments. She transfers her assets into a blind trust, overseen by an independent trustee. That trustee then sells the existing holdings (either all at once or over time) so that when Johnson has to vote on a bill affecting the tech industry — or even affecting her old company — she doesn’t know whether that vote could affect her personal finances.

But Trump’s situation is far from typical. Most of his wealth isn’t held in stocks or bonds that can be easily sold; it’s in a company that he owns and operates, it’s in buildings and golf courses around the world, and it’s in his personal brand (and the licensing deals based on it). Simply transferring his assets to a blind trust wouldn’t accomplish much as long as the company remained in business. “President Trump can’t un-know he owns Trump Tower,” Dillon said Wednesday.

To put his assets in a true blind trust, Trump would need to liquidate his assets by selling the company and its holdings, stripping his name off his hotels and resorts, and canceling his licensing deals. Dillon on Wednesday argued that such a plan would be impractical if not impossible. Some of her reasons boiled down to one: It would cost Trump a lot of money. She argued, for example, that if Trump sold his assets without retaining the rights to his brand, he would “greatly diminish the value of the assets and create a fire sale.” In other words, she said, the assets would be worth far less without Trump’s name on them.

But there are practical hurdles to a true blind trust even if you aren’t worried about Trump’s personal net worth. The process of selling his assets would take time, perhaps years. And because the sales would undoubtedly make headlines, Trump could easily keep track of what he still owned and what he didn’t, meaning that even then the trust wouldn’t be truly “blind.” (It would also create the strange situation of having a business named after the president of the United States but not controlled by him.)

So Dillon is probably right that a blind trust isn’t a viable option for Trump. But that doesn’t mean Americans should dismiss concerns about conflicts of interest. Those conflicts are real, whether or not they are readily avoidable. Trump owns — and does not plan to sell — assets in foreign countries. His domestic business is affected by laws and regulations — labor laws, environmental regulations, immigration policies — that Trump will control or influence. His company borrows money from banks that Trump’s administration will regulate. As my colleague Maggie Koerth-Baker wrote last week, those conflicts could influence Trump’s decisions even if he makes every effort not to let them.

Dillon laid out some steps that Trump will take — voluntarily, she emphasized repeatedly, because the president isn’t bound by conflict-of-interest laws — to mitigate potential conflicts. Among them: Trump will give up the management of his businesses to his sons, who have agreed not to make any new international deals while he is president. Domestic deals will go through a “rigorous vetting process” by an ethics adviser, and Trump won’t be involved in such decisions or even know about them. (“He will only know of a deal if he reads it in the paper or sees it on TV,” Dillon said.) And in perhaps the strangest provision of the new policy, Trump will turn over to the U.S. Treasury “all profits from foreign government payments made to his hotels,” as a way of avoiding what some experts have argued would be a violation of the Constitution’s emoluments clause. (It isn’t clear how such profits will be defined, or who would get to make that determination.)

It’s hard to evaluate Trump’s promises because as a private company, the Trump Organization doesn’t have to disclose many details about its finances or operations and because Trump himself — in a break from the practice of past presidents — has refused to release his tax returns. Trump on Wednesday displayed huge stacks of documents that he said were part of the process of turning his business over to his sons, but he didn’t make those documents available for public inspection. So although Trump did, as promised, provide new details about how he will handle his finances as president, the news conference didn’t do much to change the bottom line: When it comes to conflicts of interest, Trump’s message to Americans remains, “Trust me.”