Some FAQ states that when two Characters are both in the Pits space, they can't encounter each other. BUT if one of them gets turned in to a Toad and drops all it's items and followers, is it still possible for the other character to pick these up in the beginning of it's turn? As they can't encounter each other, it might be that it is considered that they actually are in separate "containers" although in the same space and therefor the dropped items and followers aren't available for other characters in the same space.

We don't even need the FAQ for that. - Basic Rules, Page 19: "In the Inner Region, a character may only encounter another character on the Plain of Peril, the Valley of Fire and the Crown of Command."

No need to make anything more complicated. Both characters are on the same space and will be encountering the same space, therefor:
If you are on the Pits with another character that gets turned into a toad while you are still dealing with the Pits Fiends, the answer is yes, you can pick up the stuff that was dropped before the next fight. (This doesn't work if you've already defeated all your Pit Fiends when the other character lands on the space.)