Liverpool 0-1 Arsenal: Alexander Isak-Jurrien Timber shirt pull and Noni Madueke-Alexis Mac Allister 'headbutt' show good and bad sides of VAR
Alexander Isak was not awarded a penalty during Arsenals win at Liverpool, despite Jurrien Timber pulling his shirt; nothing was given on-field or by VAR; Alexis Mac Allister went down after touching foreheads with Noni Madueke; VAR reviewed, but did not send off Arsenal man
