Transmission oil change 3 gallons low

While I agree with Dons post, if the dipstick is the one that you check through the floor of the bedroom and comes straight up from the tranny, it's a Allison dipstick which will be accurate.
Putting dirty oil back in is BS as you only loose a couple of quarts of oil when you change the primary filter. I'm afraid with the answers you got I'd go up the Freightliner food change with my complaint.