Napkin math: earth's surface area is ~510 million square kilometers. The lander is described as fitting in a 1-meter protective shell. So we have a roughly 1 in 510 billion chance of standing in the lucky spot.
(This of course would only be accurate if all square meters of the earth's surface were equally likely to be hit. Not the case since the lander appears to be orbiting the equator.)
The distribution of people is not uniform over the potential impact area, which is, as you mention yourself, not the whole surface of the earth. The error bars on this are too huge even by napkin standards, for this to work as an estimate.
That's assuming it comes straight down. Given that most people are somewhere around one to two metres tall, if it came in at a shallow angle it could ruin hundreds of people's day.
I think the shallow angle is unlikely since all horizont speed is not going to be compensated by anything, once it's gone by air friction, it's gone. Whereas vertical speed is helped by gravity. It of course depends on the initial velocity, but I doubt it's high enough for it to be an issue.
(This of course would only be accurate if all square meters of the earth's surface were equally likely to be hit. Not the case since the lander appears to be orbiting the equator.)