Why are you doubting about this? I believe you know it very well that a deposit gets credited to the account of the users in a casino when it receives the required number of confirmations. 40 LTC isn't a big deal for Stake, and they always credit such small deposits and process withdrawals instantly (if the required wagering is completed).

I think you haven't observed the address yet in which Bitpanda team sent the refund. There were already some incoming transactions on that address when the 40 LTC transaction had come from Bitpanda. It means the user was playing at Stake when the deposit reflected in his account. The user has either lost or withdrawn the funds which he received for Bitpanda mistake. This is why Stake isn't liable here to pay the 40 LTC to OP. I hope you understood the main point here.