Rather unlikely - pseudosuchian archosaurs (e.g. 'rauisuchians' ) which are usually considered as the producers of tracks referred to ichnogenus Chirotherium were well adapated to terrestrial locomotion (some show trend towards bipedalism). There is a curvature in metatarsal/ pedal digit V reflected by imprint morphology but in Triassic archosaurs this feature has arguably nothing to do with grasping or alike.
You might also have a look at publications by Hendrik Klein and/or Hartmut Haubold about Chirotherium trackmakers.
http://scholar.google.de/scholar?q=klein+haubold+trackmaker&hl=de&as_sdt=0
There does seem to be a trend toward bipedalism in chirotheriod ichnotaxa. The metatarsal/pedal digit V as illustrated by Klein & Haubold (2007), particularly their Figs. 2 and 5, show both a well-muscled, recurved digit V and a palm-like depression running across each print that may suggest grasping capability. Perhaps this would have been useful for climbing trees chameleon-style, or moving over fallen branches?
Some chirotheria with recurved toe V are gigantic with producers reaching 8 meters in length (an arboreal lifestyle can be ruled out).
See e.g. Demathieu & Demathieu 2004, Fig 5 for an interpretation of ankle and foot morphology:
http://www.tandfonline.com/doi/abs/10.1080/10420940490444898
Perhaps getting grip on soft and wet substrates or walking on uneven grounds are the better idea for functional advantages of a handlike foot morphology . Later producers of chirotheroid tracks display a tendency towards digitgrade walk and thus imprints of the heel pad and fifth toe become smaller until they are entirely absent.
How real tree-living relatives of archosaurs looked like? See drepanosaurs (studies by Silvio Renesto):
https://www.researchgate.net/search.Search.html?query=renesto+drepano*
The digits in Chirotherium do not appear to vary much in their relative positions which you would expect if they rotated in the manner of an opposable digit. Without skeletal remains, it is difficult to be certain of the nature of the joints, but my guess is that chirotheroids did not have joints that allowed opposition. See my landmark plots (fig 10) on my Isochirotherium paper - there is not a lot of movement in the digits.
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