Aramu is not mentioned again after he alerts the group about the birds' behavior changing. Since he was attacked after Adam, it may have been possible to save him if he wasn't forgotten about.
When Ryan is looking at the single bird on the beach there is a clear blue sky behind him but when the shot changes to the Doctor & Suki, with Ryan directly behind them, the sky is full of birds.
The phone number seen near the start of the episode (+85207700900781) is impossible. +852 is the code for Hong Kong (correct so far), but it should be two sets of four digits, not a five-and-six UK mobile number.
Also, a country code can never have a 0 after it, as this would make the original number begin 00, which is the code for dialling abroad again.
Praxeus is supposedly a highly contagious pathogen. So much so that the Doctor warns that one scratch from a bird will infect them. Yet when Praxeus makes someone's entire body explode into a fine mist of tiny particles and people breathe those particles in, somehow they don't get infected.
When the lab on the beach is attacked & everyone runs outside, the birds fly into the air but do not chase anyone until they're practically at the Tardis.