I think FWIW Barry planted her phone.
Recall the early report from LE having located an item/article. Item = phone? helmet? Article = of clothing? helmet?
I think what's key is Barry didn't know either. He knew what he planted; he didn't know what they found.
When he asked LE if they found her phone, IMO it meant he planted it to be found OR he knew they would be looking for it and he knew they couldn't find it. Ever.
I think it's the former. And I think he was genuinely flummoxed. Wanted to know what they did or didn't find.
I think he was in the water looking for it. I think he wanted LE to dredge the river -- to find the phone (or to waste time looking where he knew they wouldn't find her).
I think he texted her phone as a test, hoping to learn LE had it. Somehow in their hands, watching weirdly for incoming messages. I think he was sleuthing. (Though it could've been for the benefit of those tracking HIS messages. See, I care about my wife.)
I wish somebody could find her phone. I believe it's out there. And I believe it's damaged. Extensively. More than would be warranted from a bike ride/ accident that never happened. Weird. Bike's fine. Helmet's fine. Phone, destroyed
JMO