Doing two different quest hand ins at once will cause one hand in to be eaten.
 

https://wiki.project1999.com/Innoruuk_Symbol_Quests

Handed
https://wiki.project1999.com/Halflin...aster%27s_Head

and

https://wiki.project1999.com/Leatherfoot_Raider_Orders

to

https://wiki.project1999.com/Draxiz_N%27Ryt

in the same trade.

Draxiz gave the reward for the Halfling Druid Master's Head hand in, but not for the Leatherfoot Raider Orders (which he apparently just ate).

I imagine this problem of attempting multiple quests unsuccessfully isn't unique to this situation.

There are many quests where this will currently work, and some where it will not. It is part a larger overhaul needed for scripts.