DAE get burned by the 'just replace the whole control board' advice?

A tech with 20 years on me told me last month to always swap the whole control board on a no-heat dryer instead of testing the thermal fuse first. I did it his way on a Tuesday call in Fresno, threw a $180 board at it, and the thing still wouldn't heat. Turned out the thermal fuse was blown from a clogged vent, a $12 part I skipped because I trusted his shortcut. Customer paid me for the board and I ate the cost of the second visit plus the fuse, so that 'advice' cost me about $220 in parts and gas. Now I meter the fuse and check airflow before I even touch a board. So who else has a story where a veteran's shortcut backfired on you, and what was the part you wish you'd tested first?