Gerald had, of course, heard the shots from behind him as he gathered himself from the landing. Turning behind him, he looked up to see a dead nevermore and what appeared to be a girl wearing a cloak. 

Gerald could see very practical reasons for wearing a cloak. Having a cloak allowed one to conceal their hand movements, something which Gerald ascribed and respected, having also taken the same concept in having a long coat. Cloaks also helped conceal body language, something Gerald found very helpful. The hood of the cloak even concealed one's identity. But even then, there was still that one little fact that, even - or rather, especially - taking all of this into account, that had Gerald extremely concerned. 

Each and every single advantage he had just listed was designed to work against humans. Not Grimm; humans. Beowolves didn't memorize specific faces by sight, humans did. Ursas didn't read body language, humans did. Her wearing a cloak was a warning sign - a warning to Gerald that his new partner was going to be hiding things. Of course, he could have been wrong and she could be using the cloak for completely other reasons - possibly even just fashion - but Gerald always hoped for the best and assumed the worst. 

"...Well hello there," Gerald said with a smile straight off the bat, not bothering to comment on the fact they were partners for he found no reason to voice the obvious - "Gerald Tarius. Jack of all trades, odd jobs specialist and handy man. Pleased to meet you." he said, offering his free left hand up for a handshake despite the fact she was looking down at him.