Would you risk going back to a live LV just to check it out? Take the risk that Harry didn’t notice some annoying bystander get dispatched, or just didn’t mention it? A lot of those revelations only came out when the subject came up, after all. Using a Pensieve would be much safer.
You assume Snape isn’t one of the headless minions on the ground...
Snape isn’t, because he can’t apparate from Hogwarts. Amusingly, Snape may interpret his exclusion from the mass sacrifice as a deliberate “kindness” from the Dark Lord.
Would you risk going back to a live LV just to check it out? Take the risk that Harry didn’t notice some annoying bystander get dispatched, or just didn’t mention it? A lot of those revelations only came out when the subject came up, after all. Using a Pensieve would be much safer.
You assume Snape isn’t one of the headless minions on the ground...
Just watch from a distance, using a telescope.
Snape isn’t, because he can’t apparate from Hogwarts. Amusingly, Snape may interpret his exclusion from the mass sacrifice as a deliberate “kindness” from the Dark Lord.