One of us is salafi and sometimes he leads salah,but most of the time I lead salah,Is it permissible to pray behind a salafi

We pray in our office,One of us is salafi and sometimes he leads salah,but most of the time I lead salah,Is it permissible to pray  behind a salafi ,generally we try to avoid but sometimes due to unavoidable circumstances,like i am late or not around, he leads.please note that we are a small group of 6 people in office and sometimes I pray behind this salafi imam just to keep the unity and not create any conflict due to this act.As a general this salafi guy keep criticising all madhahib followers and even tabligh jamaat activities.Please reply clearly whether I should totally refrain from praying behind him or I can atleast repeat my salah later on.