Abe arrived with both Marcus and Aknot and avoided everyone, including the Order. They would have been almost the last people into the church and would have stood in a back corner. Abe's face would have been expressionless but anyone close enough to see his eyes would have seen the profound sorrow and grief in them. Marcus and Aknot would have alternated between paying attention to the service and keeping a very careful eye on Abe.
They would have waited for everyone else to leave the church then followed and apparated away as soon as humanly possible, once again not speaking to anyone. They would have returned to the Hog's Head where Abe would have immediately gone upstairs, leaving Marcus and Aknot to run the bar with instructions that he was not to be disturbed... by anyone.