Nothing against Reirden but Trotz is one of the best coaches in the league and finally got the Caps over the top.

During that 17-18 season, they had already made the call to let him walk and they denied multiple teams' request to talk to Reirden. So between saving money, being fair to Reirden and being unwilling to reassess their attitude toward Trotz (and GMBM did not see eye to eye on some fundamental things), they gave Trotz a bullshit offer to say "well, we 'tried' to retain him." I can't imagine how anyone would have thought that would end well. Losing Reirden as an assistant also hurt, but that would have happened either way.