Umm, because the pt. is in hemorrhagic and neurogenic shock.
Pt. is bleeding from the abdomen, Approx. 1 liter is found on the ground.
What would you do?
I don't recommend a full liter bolus, instead, dosed bolus' to maintain a systolic of around 100. They are correct in saying that you need to get the sats up, but that really shouldn't be an awfully difficult task.
If the pt doesn't respond to dopamine, Atropine is not a bad choice, but let us never forget our friends epi, and nor-epi! Hopefully, if you get the heart rate up, the blood pressure will follow.
As for fluids as a general rule, a lot of people feel it's appropriate to just automatically do a liter bolus with a shock trauma, but keep in mind, that's a way of the past. You don't want to cause any more anticoagulation issues than need be, and you don't want to dilute whatever blood is left in the person, so instead of just opening it, and ignoring it, just stick with a dose bolus of 100 at a time just keep that systolic up around 100.