Hmm, not exactly intended, but perhaps an acceptable variant. The intended way uses a different creative trick not seen in many custom levels. Looks like the trick I showed you on Hellish 19 of Sublems came in handy here, even though it's not necessary to solve either level. Then again, the easiest fix I can think of here to block off your solution is to simply extend the OWW to the entire wall, including the top. Let's see if Icho agrees.
As for checking the version, Dovelems is one of the few packs that doesn't display the version of the pack anywhere in the main menu, including the scroller at the bottom in the main menu, so instead you'll have to check the dates of the affected levels and match it up to the date that the updated version was released in this topic. However, I can tell you that from watching the replay that you have the up-to-date version of Devilish 25. I'm just not sure if you have the most recent version of the pack, v2.9, which is dated September 6 this year. There were a lot of levels that got updated with this one, so you'll have to check if any of the levels affected are dated September 6 in your NL directory. If you find any, then you have the most recent version of the pack. If not, you can download the latest version in the OP.