Plot hole: I can somewhat understand that in a kiddies' show all aliens can inexplicably speak English - but using Terranean (i.e.: Arabian) numbers as well? While Tetrax's computer uses alien runes, the readout on Gluto's holographic HUDs use Arabic numbers - somewhat a bit too deliberate a producer choice to emphasize intergalactic communication.
Plot hole: After the first death, Ian is in the office and after the conversation with the girl the scene starts to speed up, indicating that time is passing by at a fast pace; yet even with the rapid time change, the sun's rays that pass through the office never move or change in any way as it should.
Plot hole: Brewster gives Erica his gun to shoot the last perp, but it was HER gun that shot the other two. Brewster is going to have to convince investigating officers that the one perp killed the other two...or would they even care?