He's not making things up. I experience massive delay with bluetooth headphones, and speakers. The delay is not one second, but it's enough to make it useless for watching video.
What is the delay? For me it is imperceptible (it means it is below 50ms).
I see here a lot of people talking about delays and how $2 wired earphones solve the problem. So I get people buy cheap and wants quality with their new iPhones. Cheap earphones with or without wire are always crap, the sound is horrible and the quality follows. It might be the reason of the delays: cheap stuff
Apple has mastered hiding any delay with AirPods and perfectly syncs things up. No small feat because it has to sync up both left and right in addition to what’s on the screen.
I've never seen bluetooth audio devices that were capable of syncing video and audio in 10 years of using bluetooth audio devices. My most recent tao tronics BT headphones were great for podcasts and audio, but useless for watching video from my Moto X. Have also tested this with Anker portable speakers, Amazon Echo in BT mode, and Creative BT speakers. All are useless for video. I replaced them with a set of $9 Panasonic wired Earbuds that sound just fine and never run out of batteries.
It also depends on the device (and software) you're watching video with - some are smart enough to compensate for the lag. iOS is decent at it when something uses the system APIs to play video (so not VLC), but I never had any luck back when I used Android. On that Mac I get really bad sync issues sometimes (seconds!).
I use Bluetooth and never had issues with delays. I had couple of computers, couple of mobiles and 3 different Bluetooth headset during this time. My Bluetooth headsets weren't the cheapest ones either.