"The plane landed safely and on schedule around 12.55pm but remained on the runway for around 20 minutes until it was towed off."
While I only visit LHR occasionally, I am puzzled why it would take 20 minutes to tow the aircraft clear of the runway.
Seems to me that
prior coordination with company could have made a tug ready and available;
coordination with airport emergency services could have placed the tug in close proximity to the runway; and
coordination w/ ATC could have put the a/c in holding until all was ready
resulting in a runway closure of less than 5 minutes to get the a/c clear and on the way to the gate - and probably no news story as a consequence...
...or am I being unrealistic?