In previous posts, I noted that the COA had AWOP'd a case in which the defendant argued that DUII-alcohol and PCS (from the same traffic stop) were from the same criminal episode. (It was a double jeopardy argument, but the definition of separate criminal episodes doesn't change in any meaningful way when the phrase is used at sentencing or for the purposes of joinder.) The COA implicitly held that the crimes were from separate criminal episodes.
Well, maybe you don't want to cite an AWOP'd case to your trial court (which is correct; AWOP'd cases have no precedential value). So here are other cases in which the charges were deemed to be from separate criminal episodes. If you have a caseload that is majority criminal defense, it seems highly unlikely to me that you don't have at least one case where counts are improperly joined.
State v. Crumal, 62 Or App 156, 158-61, 659 P2d 977 (1983) (disorderly conduct offenses at hospital arose out of separate criminal episode from burglary, assault, and criminal mischief offenses that occurred roughly 45 minutes earlier at a residence); State v. Paquin, 55 Or App 676, 678-80, 639 P2d 694, rev den, 292 Or 863 (1982) (possession of drugs and weapon offenses arose out of separate criminal episode from reckless driving offense even though the defendant may have possessed the contraband items when he drove recklessly); State v. Yock, 49 Or App 749, 751-54, 621 P2d 592 (1980), rev den, 290 Or 727 (1981) (DUII offense arose from separate criminal episode from burglary offense that occurred minutes earlier); State v. Oliver, 26 Or App 331, 333-35, 552 P2d 562 (1976) (illegal-possession-of-elk offense arose out of separate criminal episode from theft-of-steer offense that the defendant had just committed and driven away from).
As you know, joinder can still take place, even involving charges from separate criminal episodes, if the crimes are part of a common scheme or plan or they are same or similar crimes. Most of the examples above wouldn't qualify for those categories either (although I'm guessing possession-of-elk and theft-of-steer would probably be properly joined).
If you need sample "improper joinder" demurrers, or more discussion on the topic (including strategic advantages), you can find them on this website.