Originally Posted by nacho

Re-tarmacking the runways is not something happened "suddenly", so it shouldn't be treated as extraordinary. If airlines knew about this in advance and still sell tight connection like that - it's 110% their fault.

I'd file a claim with LH as your friend entered a contract with LH, not the other airlines. LH can go after LX/SK to get that 600 EUR back. However, getting that from LH will require plenty of patience and possibly a letter of demand physically post to their legal department.

It was possible to do that connection within 20 minutes with small kids - it helped a lot when CH wasn't part of Schengen so passport control was done at CPH, and at ZRH it is treated as airside transfer so no security, border control etc. Now I wouldn't do that (honestly haven't flown LX for a long time due to its poor mileage accrual).