The conversation between Commander Vishniac and the TV newscaster could not have taken place in real time as the distance between Earth and Mars is 3-5 light minutes, which means every message exchange would have been delayed by 6-10 minutes, the time for message and answer to cross the interplanetary distance.
The space helmets aren't really airtight. When Rodrigo and Sanchez are in the Martian maze and get to the hall where there is oxygen, they just lift the bottom of the masks, which are just resting on the fabric covering their necks.
After Johnson and Baglioni leave the spaceship, Baglioni turns slightly and you can see through the gap in the mask.
When talking about extravehicular activity, Susana pronounces the acronym EVA like a word "eva". This acronym is never pronounced like a word, but rather the letters are said individually.