Reaper was mistaken in thinking the Wolkar was only worried about traps. He was worried about the traps AND the soldiers that would come and attack him while he was pinned or immobilized. He drew both pistols  and started up his visor's spectral scans, going through thermal and even motion tracking so he would still be aware of Reaper's position. Better to know your partner's angle when you came upon a set of enemies and figure which he would most easily be able to take. 

He approached the first possible landing site, peeking up through the jungle brush to see if there was any activity.