The UK government report on how Huawei released software for its network equipment states that the software images are compiled per client. There is no way to actually verify their stuff can be trusted when every customer has a different version of an image even if the hardware is the same.
How can you trust it when it has this policy.... how do you know your Huawei equipment doesn't arrive with a backdoor? The process of each company having to verify that that particular piece of network equipment is not backdoored is exponentially complex and can not be feasibly verified.