Most likely wet-lay, as it's difficult to keep the weave pattern looking straight when applying resin by hand. There's no reason why the pattern shouldn't be completely straight when infusing.  

As Hanaldo said, assuming that infused parts haven't been made with an in-mould coating, the only obvious way of telling the difference between those and pre-preg parts would be to look at the 'B' side for evidence of the different release film/fabrics that are commonly used

The OP's parts certainly seem to be pre-preg ones, judging by the appearance of the 'B' side

Parts made in Chinese factories just aren't good quality in general, more likely to be the result of a hurried layup than a result of the process. 

Of course complex parts with extreme geometry will test both the skills of the laminator as well as the material conformability, however the parts the OP posted are very straight forward and I would expect a straight weave even with wet-laid parts.