Also. Look at the steep sides near the bench. Who knows. She could have seen something in there, leant over and fell. Slipped. Anything.
Not clear on the teams call. If she was just "logged in" or was speaking etc.
Could have easily popped phone in bench. Might have even been trying to pick something out of the river.
So many innocent scenarios that could have ended in tragedy before jumping to foul play.
It was daylight. There were people walking. It would be exceptionally Risky for someone to let's say murder her. Risky that someone else came along, she screams etc. Leaving the phone on, and in the bench, also would be weird.
Really, foul play seems much much more unlikely than an accident