I get the impression that Mr Tyler and Miss Willcox would have been happier if someone from Abellio had called them to say that they're sorry they didn't feel their journey went as smoothly as they had hoped it would after they reached Cambridge, but that they were still looking into the circumstances of this.
It would probably have also helped to have asked some more questions about what had happened after then, and to establish which trains (and other modes of transport) they had used on the way.
The £100 isn't important. It isn't important at this point whether a failing by Abellio staff on the day contributed to the customers' problems, either. What is important is that someone at Abellio knows what problems the customers experienced on their way home after the crash, and is trying to find out what led to them, and what lessons can be learnt from them.
It doesn't appear that Abellio's response left the customers feeling confident that this was the case, which is a pity.