I have experienced this bug on the NW airfield in one of the constructions (tent area). The exact position is "041 041" on this map.
http://dayzdb.com/map/chernarusplus#4.033.046

1. Kneel with weapon in hands
2. preff "f" to use the ladder

--> character will stand up and do the "v" animation and then he goes up the ladder.

The "v" animation is the wrong part ;D