>he sees that open source programs can use Qt for free and that commercial programs need to pay.

Where does it say that? Can you mention what he is having trouble with? I just took a quick glance at that link in GP and it seems to spell out the obligations of the LGPL pretty clearly on the right side, which are somewhat specific and notably don't include a requirement for your program to be open source. That requirement is only for the GPL components, which is included in the small print on the left.

So, by your own admission, the critical piece of information my boss cares about must be inferred from the fact that it is absent from a sizeable pile of relatively technical details and from the fact that no detail (especially the GPL sub-component callout) implies it in turn.

Making this inference requires you to not only have outside knowledge of open source licenses and the Qt licensing situation, but to be rather confident in said outside knowledge. That's what he had trouble with.

No, my point is that it doesn't have to be inferred, and that the relevant information does seem to be all there. IANAL and this is only based on my own understanding of those licenses, but it seems to do as good a job as a short marketing page probably could. It's not a place where they can reasonably address every common misconception about the LGPL that someone might have. Your boss can't be helped if he is going to assume the worst just from reading what amounts to a single powerpoint slide.

I think that detail about GPL could be easily missed because it's written in small print, but that's a different problem. There are a lot of Qt components so it doesn't make sense to list them all on that page. A full list that can be filtered by LGPL/GPL status is here: https://www.qt.io/features

I'm assuming by outside knowledge you mean the fine print of the license: how is any company supposed to prevent your boss from having to go over that with a lawyer? This isn't even an open source thing, it applies to anyone in the software business. And this is ignoring that the GPL is probably one of the better understood open source licenses at the moment.

> the relevant information does seem to be all there

The key piece of information is absent.

> it seems to do as good a job as a short marketing page probably could

It could have done better in a single short sentence by stating the key piece of information, rather than leaving it to be inferred laboriously from a pile of details.

> It's not a place where they can reasonably address every common misconception

No, but it could have addressed the single largest misconception. It chose not to.

Wouldn't it be logical to expect someone to consult a lawyer when making such a decision?

Are you being sarcastic?