Sadly, as with many other "asking for advice" threads, this one is seeing some jumping to the worst possible assumptions about the situation, and arguments made based on those assumptions even after the OP has cleared up the detail in question in such a way that makes it clear the assumption was incorrect.

The good advice I'm seeing is:
* Don't be confrontational or accusatory, don't say "You're wrong!" Phrase it as something like "This is how I thought this rule worked, can we stop for 30 seconds to look it up?" or something along those lines.
* Look it up, explain how you read it, give your point of view.
* Be willing to move on and not hold the game up either way, revisit after the session.
* By remaining calm and conversational about it, you let an unreasonable, clearly wrong but uncompromising, or ulterior-motivated DM demonstrate that they're the one causing the issue -- and you give a reasonable DM space to consider the question without it being a confrontation.

It's a game, and the DM is probably trying hard to get it right and be fair, most people aren't deliberately being jerks at the gaming table.