Any android worth it's price tag would have two bits of important firmware.

One protecting itself (because it's an expensive piece of equipment) and the other protecting company employees in order of rank.

I imagine what happened in the Vickers vs David tussle is David can not harm Vickers in self defense but he can regulate his body movement and maybe even adjust the distribution of his body mass (do they weigh as much as us?) to protect himself.

That way she could pin him up against the wall with her proven athleticism (this is the nearly nude pushups girl after all) aided by his body firmware positioning his body in such a way as to reduce risk to himself.

He is ordered not to divulge what Weyland said to him but he can not carry out his master's orders if Vicker's damages him in an attempt to get information out of him so it makes sense he would make a limited disclosure of information to protect his ability to carry out his prime function.

There is a complex equation built into him which balances his need to carry out instructions against self preservation in order to enable him to carry out his instructions.

This would extend to physical situations like that one too.