One thing that annoyed me and completely ruined the film

Who knows how Paul would've reacted if she were to tell them anything that had happened? He probably would've killed them all on the spot.

Come, fly the teeth of the wind. Share my wings.

i think because at that point anna and george didn't think they'd really kill them. the 2 psychos were trying to place the guilt back on them by playing mind games. they were trying to justify their violence (i.e. you smack me, i break your leg. your dog jumps on me, i kill him), so at that point it anna was believing the lies/manipulation and hoping it would all go away if she just played along and didn't cause anymore of an uproar.

It did seem quite stupid not to invite those folks to come and have a drink at the house.

When I'm gone I would like something to be named after me. A psychiatric disorder, for example.

Think about the situation. These two psychopaths have already injured your husband and killed your dog. She had no idea what they were capable of and when he said to her, "I think we both are thinking the same thing," that was kind of a hint to her that he had no problems seriously hurting her (or possibly killing her), along with the three friends in the boat.

Plus when it comes to horror movies in thrillers, you kind of have to accept some questionable actions to keep the story going.

Also didn't anyone catch on to him pointing out their home, I kind of took that as a threat to their safety.

I think she probably believed that the motive was only to rob the house, and her number one priority was to make sure her son and husband weren't killed (ironically, that is what she saw happen anyway). By not making any fuss, allowing the people on the boat to sail off, and letting the intruders get on with tying them up and looting the house, she would preserve their lives -- if she had started screaming and made a fuss there and then, the robbers may have freaked out and bashed all their skulls in with golf clubs in panic.

It is a bit hard to swallow, though, considering that the robbers were unarmed at this point, and would have been outnumbered, four (plus one child and one crippled man) on two, but people do not always act rationally or logically when terrified and under stress.

Personally, I think I would have launched myself at the guy and tackled him to the ground when they were chatting to the people on the boat; but then I am not a woman, nor a mother, and I have never been in that exact situation, dealing with the shock and fear that would be setting in.

Because the one in the house would've killed/hurt her husband and son. Or the one she was with would've run back to the house and done it.