如果分成2句话的话就是：
he did not accept the charge made by some of his critics,as he well founded the charge made by some of his critics
他不接受一些对他提出批评的批评家的指控,（即使）同时他使得这些指控成立了.
也就是说 did not accept ,和 well founded 共用主语 he,并且共用宾语 the charge.
as 理解为 连词=though,即连接2个分句.well 副词修饰 founded.founded 为过去时.因为2个分句主语一致所以省略的主语 he