How to help someone with grief?

So my friend got stood up by some guy who canceled last minute. The guy ended up going to the right place at the right time, but decided to hang out with friends instead. My friend is a bit heartbroken.I want to help him by listening and helping him process what happened. But he's currently in denial, saying maybe his mom found out and had the date block him.I'm pretty sure this isn't true? He could just tell the mutual friend why he had to cancel, and have them tell my friend. The date is 17, if he wants to find a way to communicate, I'm sure he could.I told my friend this, but I'm starting to wonder if it was a good idea? Because denial is normal. Idk if I should have just listened, when I told him his argument was a stretch instead.Thoughts?