Goodness, a/c reduces speed by 5kts and it's a controversy. Can't seem to find UA744 on flight radar, though it says delayed on TFS arrivals board. Maybe crew had ACARS update to switch off xponder before pprune talks monarch into the financial grave..... joking btw for those who can't tell.
As far as I'm aware flightradar is probably not accurate to within +/- 5kts.
All the best to the workers at MON!