The broken deal between the Queen and Ripley
In the scene were Ripley first meets the Queen Xenomorph it is shown that they come to some agreement.Basically the deal is that if the queen let Ripley and Newt leave unharmed she wouldn't use her flame thrower on the eggs. The Queen calls off the two approaching xenomorphs, however as Ripley backs out one of the facehugger eggs opens up and Ripley gives the Queen a look of incredulity understanding the the intentions and the deal is off and Ripley fires away. But did the Queen really break the deal? Can she control specific eggs to open on command? If she could why would she make so obvious and so close by endangering herself.
We know the eggs can open on their own so was it just bad luck on the the Queen. It not as if she was going to let her go and would indeed send send her reinforments after Ripley, but was the egg really her doing?