One professor even went through my entire procedure, painstakingly — I'm not really sure where he got all this time — and he went through and said why each and every step was like the worst mistake I could ever make.
Uno profesor revisó todo el procedimiento, cuidadosamente — no sé de dónde sacó tanto tiempo — revisó todo y minuciosamente en cada paso dijo por qué cada cosa era lo peor que pude hacer.