This is a 4 pitch climb. My climbing partner was leading the 3rd pitch and had to climb over a bulge to get to the next belay point, hence I couldn't see him anymore and it was harder to hear what he was saying. Soon after he went out of sight I heard him shout "safe" so I took him off belay. Then suddenly started to panic as I doubted whether he might have said "take" instead. Thankfully I was right and he was safe but that would have been one fatal mistake..