When Maciste saves the small child from the lion, the shots of the real lion (with Gordon Mitchell's stand-in for the sequence) show that the claws are not out and the paws are not being used to strike but rather happily returning the hug it's receiving.
In many shots during Maciste's fight with the lion, the lion can be heard roaring, even though it is clearly not roaring in the footage.
In the close-ups of Maciste hands during the tug-o-war over the lion pit you can see Snap Rings holding the ropes. These are the same ones sold today for use by mountain climbers and other applications.