Here is an example of an unexpected splice-modifying outcome. An oligo was targeted to i1e2, which would normally be expected to skip exon 2. Instead, the oligo caused retention of intron 1. This is the usual outcome of an e1i1 oligo, but not of an i1e2 oligo. Figure 5B shows the gel and the RNA map: https://www.cell.com/cms/attachment/2119254818/2091259359/gr5.jpg
Burns DT, Donkervoort S, Müller JS, Knierim E, Bharucha-Goebel D, Faqeih EA, Bell SK, AlFaifi AY, Monies D, Millan F, Retterer K, Dyack S, MacKay S, Morales-Gonzalez S, Giunta M, Munro B, Hudson G, Scavina M, Baker L, Massini TC, Lek M, Hu Y, Ezzo D, AlKuraya FS, Kang PB, Griffin H, Foley AR, Schuelke M, Horvath R, Bönnemann CG. Variants in EXOSC9 Disrupt the RNA Exosome and Result in Cerebellar Atrophy with Spinal Motor Neuronopathy. Am J Hum Genet. 2018 May 3;102(5):858-873. doi: 10.1016/j.ajhg.2018.03.011.