When the Alliance Agreement was signed between Weber and SMB back in 1997/8, there were defined call and put options agreed for both sides at defined times at an defined price.
Plus some other stuff - IT platform, MRO etc
It's not coming as a surprise to anyone involved and LH will have long term planning in place for the financial issues.
Won't stretch them either - they've got the lowest leverage ratio of any of the majors and one of the lowest worldwide.
Just watch LH turn the UK into their aircraft carrier using bmi as a proxy - that was the original intention and it's what they've been waiting 10 years to do...