When David is printing the photo of the bloodhound, the computer displays "One Match Found: Now Printing" and then the printer is heard heating up as if it is a laser printer. However, a shot later we see the photo printing out slowly. On two counts this is a goof: One, the printout shouldn't have come out that soon after the computer sent the signal to print (and displayed "Now Printing"), since laser printers take at least half a minute to heat up; and the printout comes out slowly, suggesting that the printer is inkjet (so it wouldn't heat up and it would make different sounds). When it receives a signal to print from a computer, a laser printer will take some time to heat up but then the printout will be made very quickly. In an inkjet printer, the paper will come out slowly (although it will come out soon after the computer sends the signal) and pause occasionally.
The bloodhound left plenty of evidence of his visit, namely paw prints, which surely the dog catcher must've noticed as soon as she saw the deck. The first thing she would've done as soon as she saw the prints would be exactly what Joe, Sam, and David did later - measure them to get an idea of what kind of dog to look for. Same with the bite marks in the chair. As soon as she saw Wishbone, no matter how much Mrs. Hernandez insisted that it was him, she should've known that Wishbone would be too small to do any of the damage. In other words, Joe, Sam, and David shouldn't have had to prove that Wishbone couldn't have made the mess - it would have been the first thing done.
Furthermore, after proving Wishbone innocent, there was no reason for them to go any further and find the culprit dog. All they had to do was, in Joe's words, "prove it wasn't Wishbone." The paw prints and bite marks that were too big to come from Wishbone should've exonerated him.
Furthermore, after proving Wishbone innocent, there was no reason for them to go any further and find the culprit dog. All they had to do was, in Joe's words, "prove it wasn't Wishbone." The paw prints and bite marks that were too big to come from Wishbone should've exonerated him.