It is possible. Robbers aren't particularly good at picking up stuff from fallen companions.
The robbers should take the things on the reindeer, although I don't know if they actually do. If you wait long enough for the robbers to have left the area the reindeer is probably gone. If you return promptly it might be in the vicinity (unless killed).
It's possible to use some calculations from the log notes to determine the location, but I don't know these myself. Using in-game measures, you can determine approximately where the robbers were by combining your knowledge of approximately the route you were taking with the overland map if the route is through uncharted territory by seeing where the charted area ends along the route. If it happened in well known territory you only have the memory of your route.
Making a map marker is the best approach, and if you just have your character wake up and the overland map provides a fairly decent indication of where the robbers are, you can make a note there, saying e.g. "Robbers 9S 15E" (I use that kind of notes when I see Njerps, both as a warning to self and as a way to find them if I decide to go back to the homestead to gear up for war before hunting them down).