He was witnessed in a place he claimed not to be in. Whether he was standing by a gate or doing cartwheels is irrelevant - he claimed not to be there.
Why didn't he either phone her again or walk up the RDP to save waiting for an hour - the same impatient boy who chased up DH twice in half an hour. Don't be daft.
He was allegedly seen waiting across from the lane where his girlfriend would have exited from RDP. Why not just admit that he’d been waiting there? After all it would certainly have been one of the places that it wouldn’t be suspicious for him to be waiting and he knew that he’d been seen.
Why didn’t he phone Jodi again? You are aware that she didn’t have a phone, aren’t you? Further he already knew that she wasn’t at her house so what was the point of calling there? Of course he could also have been wary of annoying Jodi’s mum or her boyfriend by ringing again when they had already told him that she’d left.
Ovens went into the kitchen and told Judith that her daughter still hadn’t met Luke some 50 minutes after she had left even though she only had to walk a short distance. Why didn’t she ring Luke back?