You will never miss a flight or train
As everything is planned and arranged, it is quite rare for you to miss a flight. Even if you miss a flight under the group tour, by standard procedure the travel company will bear the loss (at most times).
We missed our flight for the first time in Gatwick Airport London due to unforeseen circumstances. Thus, we spent a day in the hotel near the airport and wasted a couple of hundreds of Euro due to our missed flight. The misjudgement is due to delayed train times even though we depart from London more than three hours ahead. Thus, traveling from London to Gatwick Airport via train is 20 pounds each person one way!