There was no point sacking De Boer with the next 4 games being a likely 0 points.
Let him stay for those 4 (S'ton, Utd, City, Chelsea), with the expected 0 points seeing him sacked (as was wanted by the owners anyway), 1 or more points from those games would be a bonus & could save De Boer's job.
Instead he lost 4, got sacked, and Roy will lose his 1st 4 anyway.